H Glossary Terms

H and E staining, also called hematoxylin and eosin staining, is a common lab method that uses two dyes to color cells and tissues in a biopsy or sample. This helps doctors see the shape and structure of cells under a microscope. It is often used to help diagnose diseases like cancer. If you see this term in your medical reports, ask your care team what it means for your specific case.

H. pylori (Helicobacter pylori) is a common type of bacteria that infects the stomach lining. It can cause stomach inflammation, ulcers, and increase the risk of certain stomach cancers, including gastric adenocarcinoma and MALT lymphoma. Treatment to remove H. pylori infection can lower cancer risk. If you see this term in your medical information, ask your care team how it relates to your health.

Ha20, also known as HCD20, IMMU-106, or veltuzumab, is a type of monoclonal antibody being studied for treating certain lymphomas. It works by attaching to a protein called CD20 found on some immune cells and lymphoma cells, helping the immune system target and kill cancer cells. If you see this term, ask your care team how it relates to your specific situation.

HAART, also called combination antiretroviral therapy (cART), is a treatment for HIV that uses three or more medicines together. It helps stop HIV from making copies of itself, protecting the immune system and slowing the progression to AIDS. HAART also lowers the chance of passing HIV to others, including from mother to baby during childbirth.

Hair follicles are tiny parts of the skin where hair grows. In cancer care, treatments like chemotherapy and radiation can affect hair follicles, often causing hair loss (alopecia). Understanding hair follicles helps patients and caregivers know why hair loss happens during treatment and encourages talking with the healthcare team about what to expect and how to manage it.

Hairy cell leukemia is a rare type of blood cancer where abnormal white blood cells called B lymphocytes build up in the bone marrow, blood, and spleen. These cells look “hairy” under a microscope. The disease often grows slowly and may cause symptoms like infections, tiredness, or easy bleeding. Treatments include watchful waiting, chemotherapy, targeted therapy, immunotherapy, and sometimes surgery. Clinical trials may offer new options.

Halaven, also known as eribulin mesylate or E7389, is a chemotherapy drug used to treat certain breast cancers and a soft tissue cancer called liposarcoma, especially after other treatments have been tried. It works by stopping cancer cells from dividing and growing. Patients may see different names for this drug in medical reports or treatment plans, so it’s helpful to ask the care team how it applies to their specific situation.

Haldol, also known as haloperidol, is a medication used to treat certain mental and neurological conditions. It helps control symptoms like agitation, hallucinations, and acute psychosis. A long-acting form called haloperidol decanoate is often given by injection to people who have trouble taking pills regularly. Haldol may be used in cancer care to help manage symptoms such as severe nausea or confusion.

A half-sibling is a brother or sister who shares only one parent with you, either the same mother or the same father. In medical and family history contexts, half-siblings are considered second-degree relatives because they share about 25% of their genes. Understanding this relationship can be important when discussing family health history, including cancer risks, but the term itself is not a diagnosis or treatment recommendation.

The Hallelujah Diet is a nutrition plan sometimes discussed in cancer care for its potential effects on nutrition, metabolism, inflammation, digestion, immune health, and treatment tolerance. It is considered an alternative diet approach and should be reviewed carefully with healthcare providers to understand its safety and role alongside conventional cancer treatments.

A hallucination is when a person sees, hears, smells, tastes, or feels something that isn’t actually there. In cancer care, hallucinations can sometimes happen due to the illness itself or as side effects of treatments. If you see this term in your medical notes, it’s important to ask your care team what it means for you personally, rather than assuming it is a diagnosis or treatment plan.

Halofuginone Hydrobromide is a substance being studied for its potential to slow the growth of connective tissue and block new blood vessels that tumors need to grow. It is a type of antiangiogenesis agent. Patients should discuss with their care team how this term relates to their specific situation rather than seeing it as a diagnosis or treatment recommendation.

Haloperidol, also known as Haldol, is a medication used to treat mental and neurological conditions such as agitation, hallucinations, and delirium. It can be given as a pill or injection, including a long-acting form for people who have trouble taking pills regularly. In cancer care, it helps manage symptoms like severe nausea and confusion. It may cause side effects, especially at higher doses, so careful use and monitoring are important.

Halsted radical mastectomy, also called radical mastectomy, is a type of breast cancer surgery that removes the entire breast, lymph nodes under the arm, and chest wall muscles beneath the breast. It was once the most common surgery for breast cancer but is now rarely used. It may be considered only if cancer has spread to the chest muscles. Patients should ask their care team how this term applies to their situation.

A hamartoma is a benign (non-cancerous) growth made up of an abnormal mix of cells normally found in the area where it grows. It can occur in various parts of the body like the skin, mouth, or digestive tract. Some inherited conditions, such as Cowden syndrome, cause many hamartomas and increase the risk of certain cancers. If you see this term, ask your care team what it means for your health.

Hand-Foot Syndrome, also called Palmar-Plantar Erythrodysesthesia, is a side effect of some cancer treatments. It causes redness, swelling, pain, numbness, or tingling in the palms of the hands and soles of the feet. These symptoms can affect daily activities and should be reported to your healthcare team for proper management.

A haploidentical donor is a family member, like a parent, child, or sibling, whose tissue type partially matches a patient’s for stem cell or organ transplant. This type of donor is considered when a fully matched donor isn’t available. It’s important for patients and caregivers to discuss with their care team how this applies to their specific situation rather than assuming it means a particular diagnosis or treatment.

Happy Major, also known as burdock or lappa, is a plant whose root and seeds have been used in traditional medicine. It may have antioxidant properties and is sometimes mentioned in discussions about natural supplements in cancer care. However, it is not a standard or proven treatment for cancer. Patients should discuss any use of Happy Major with their healthcare team.

The hard palate is the front, bony part of the roof of the mouth. In cancer care, it may be involved in cancers of the mouth or throat. Knowing about the hard palate helps patients understand their diagnosis, symptoms, or treatment plans. It is important to ask your care team how this term applies to your specific situation rather than assuming it describes a diagnosis or treatment by itself.

Hashimoto Disease, also called autoimmune thyroiditis or Hashimoto thyroiditis, is a condition where the immune system attacks the thyroid gland. This can cause the thyroid to produce less hormone, leading to symptoms like tiredness, weight gain, and dry skin. Knowing about this condition is important during cancer care because thyroid health affects how patients feel and respond to treatments.

Hashimoto Thyroiditis, also called autoimmune thyroiditis or Hashimoto Disease, is a condition where the immune system attacks the thyroid gland. This often causes the thyroid to produce less hormone, leading to symptoms like tiredness, weight gain, and dry skin. It is more common in women and can run in families. Understanding this condition is important during cancer care because thyroid health affects how patients feel and respond to treatments.

Hawthorn fruit is the small, edible berry from the hawthorn tree or bush. It has been used in some cultures as food and traditional medicine, including for heart and digestive health. In cancer care, it may appear as part of herbal mixtures or dietary discussions. Patients should always ask their care team how hawthorn fruit relates to their individual care rather than assuming it is a treatment or diagnosis.

A hazard ratio is a number used in cancer research to compare how often an event, like death or disease progression, happens over time in one group of patients versus another. It helps researchers understand if a treatment might improve survival compared to another treatment or no treatment. For patients, it’s important to discuss what a hazard ratio means for their individual situation with their care team.

HBOC Syndrome, or Hereditary Breast and Ovarian Cancer Syndrome, is an inherited condition that raises the risk of breast cancer (especially before age 50) and ovarian cancer. It is most often caused by changes in the BRCA1 or BRCA2 genes. People with HBOC may also have higher chances of other cancers, like pancreatic, prostate, and melanoma.

HBV stands for hepatitis B virus, a virus that causes liver inflammation and can lead to serious liver problems, including liver cancer. A vaccine is available to help prevent HBV infection. If you see HBV mentioned in your medical records or discussions, it’s important to ask your care team what it means for your health, rather than assuming it is a diagnosis or treatment plan.

Heterocyclic amines (HCAs) are chemicals that form when meat, poultry, or fish is cooked at high temperatures, such as frying, grilling, or barbecuing. These substances have been found to cause changes in DNA in lab studies and may increase cancer risk. HCAs are one of several chemicals studied for their possible link to cancer, especially when meats are cooked well done or over open flames.

Hepatocellular carcinoma (HCC) is a type of liver cancer that starts in liver cells called hepatocytes. It is the most common form of primary liver cancer in adults. Certain conditions, such as chronic infections with hepatitis B or C viruses, non-alcoholic steatohepatitis, chronic alcohol use, and cirrhosis, can increase the risk of developing HCC. Understanding this term in context helps patients and caregivers discuss diagnosis and treatment with their care team.

HCD20, also known as Ha20, IMMU-106, or veltuzumab, is a laboratory-made protein called a monoclonal antibody. It is being studied as a treatment for certain types of lymphoma by attaching to a protein called CD20 on some immune and lymphoma cells, helping the immune system target and kill cancer cells. If you see this term, ask your care team how it relates to your care.

Human corticotropin-releasing factor (hCRF) is a natural substance made by the brain that may help reduce swelling (edema) in the brain. It is being studied as a possible treatment to ease symptoms caused by brain swelling, especially in brain cancer. Patients may see this term in medical reports or discussions, and it’s important to ask the care team how it relates to their specific situation.

HCT, or hematocrit, is a blood test that measures the percentage of red blood cells in your blood. It is usually part of a complete blood count (CBC) and helps check for conditions like anemia, dehydration, or effects of cancer and its treatments. Understanding your HCT results is best done by discussing them with your healthcare team, as the number alone does not provide a diagnosis or treatment plan.

HCV, or hepatitis C virus, is a virus that infects the liver and can cause inflammation called hepatitis. Some people may have symptoms within a few months after exposure, but many do not. If untreated, HCV infection can lead to serious liver problems like cirrhosis, liver failure, and liver cancer. It spreads mainly through contact with infected blood. Early diagnosis and treatment can prevent complications.

HDAC stands for histone deacetylase, an enzyme that changes how DNA is packed inside cells by removing small chemical groups called acetyl groups from proteins called histones. This process can affect gene activity. Drugs called HDAC inhibitors are being studied and used in cancer treatment to help control cancer cell growth. If you see HDAC mentioned in your care, ask your medical team what it means for your situation.

HDAC inhibitors are substances that block enzymes called histone deacetylases. By doing this, they can stop cancer cells from dividing and growing. These drugs are being studied as treatments for some cancers. If you see this term in your care, it’s important to ask your healthcare team how it relates to your specific situation rather than assuming it means a diagnosis or treatment plan.

HDAC Inhibitor SNDX-275, also called entinostat or SNDX-275, is a drug being studied for cancer treatment. It works by blocking enzymes that cancer cells need to grow and divide. This drug is not yet a standard treatment but is being tested in clinical trials for several types of cancer. If you see this term, ask your care team how it relates to your care.

Hereditary Diffuse Gastric Cancer (HDGC), also called Familial Diffuse Gastric Cancer, is a rare inherited condition that raises the risk of a specific type of stomach cancer affecting the stomach lining. It is caused by changes in the CDH1 gene passed down in families. Women with HDGC also have a higher chance of developing a certain type of breast cancer that starts in the milk glands.

HDR, or High-Dose Radiation, is a type of radiation therapy that uses a higher amount of radiation than typical treatments. It is carefully aimed at the tumor to kill more cancer cells while protecting healthy tissue. HDR may be mentioned in your treatment plan or reports, so understanding this term can help you discuss your care with your healthcare team.

HE4, or Human Epididymis Protein 4, is a protein that may be found in higher than normal amounts in some cancers, especially ovarian epithelial cancer. Measuring HE4 levels in the blood can help doctors plan treatment or check if cancer is getting worse or has come back. It is one of several tumor markers used in cancer care.

Head and neck cancer refers to cancers that start in the mouth, throat, voice box, nose, sinuses, or salivary glands. Most begin in the thin, flat cells lining these areas. Common risk factors include tobacco use, heavy alcohol use, and infection with certain types of human papillomavirus (HPV). Symptoms may include a sore throat that doesn’t heal, lumps in the neck, or trouble swallowing. Treatment depends on the cancer type, stage, and overall health.

Healing Foods Diet is a nutrition approach discussed in cancer care for supporting nutrition, metabolism, inflammation, digestion, immune health, and treatment tolerance. It may be mentioned as part of supportive care or alternative cancer treatment claims. Patients should review any diet changes with their healthcare team to ensure safety and fit with their cancer treatment and overall health.

Healing Touch, also called Therapeutic Touch, is a type of energy therapy where practitioners use their hands to balance or strengthen a patient’s vital energy. It is being studied in people receiving cancer treatment to see if it can improve quality of life, support the immune system, or reduce side effects. While some use it as a complementary approach, scientific evidence does not support claims that it can treat cancer or other diseases.

A health care provider is a licensed person or organization that offers medical care, diagnosis, and treatment. This includes doctors, nurses, therapists, pharmacists, hospitals, clinics, and other health centers. They help manage health conditions, provide tests, prescribe medicines, and support your overall health. This entry helps connect the word with diagnoses, testing, treatments, supportive care, research notes, protocols, media, books, people, organizations, and safety concerns.

A Health Care Proxy is a legal document that lets you name someone you trust to make medical decisions for you if you become unable to do so. It is also called Durable Power of Attorney for Health Care or Medical Power of Attorney. This person, often a family member or close friend, can help ensure your health care wishes are followed during serious illness or treatment.

Health disparity means differences in cancer risk, diagnosis, treatment, and outcomes that happen because some groups face barriers to good health care, healthy food, or safe places to exercise. These differences often affect people based on race, ethnicity, income, or where they live. Research and programs aim to reduce these gaps and improve cancer care for all.

Health equity means that everyone has a fair chance to be as healthy as possible, no matter their race, ethnicity, income, or where they live. It focuses on removing barriers that keep some people from getting good health care, healthy food, or safe places to exercise. In cancer care, health equity aims to ensure all groups receive fair prevention, diagnosis, treatment, and support.

NaturalNews Natural Cures / Health Freedom Advocacy is a media and advocacy movement focused on natural health, nutrition, and critiques of conventional medicine. In cancer care, it may be mentioned for claims about natural anticancer treatments, symptom relief, nutrition support, or improving quality of life. Patients often explore it to feel more in control or to complement standard treatments. Always discuss such approaches with your healthcare team to ensure safety and coordination.

Health history, also called medical history, is a record of your past and current health conditions, allergies, surgeries, medications, and lifestyle habits. It also includes health information about your close family members. Knowing your health history helps your healthcare provider understand your risks, guide screenings, and plan care, especially for conditions like cancer or genetic disorders.

The Health Insurance Portability and Accountability Act (HIPAA), also known as the Kassebaum Kennedy Act, is a U.S. law that protects the privacy of your health information. It helps keep your medical records safe and gives you the right to see your health records and control who can access them. It also helps workers keep health insurance when changing or losing jobs.

A health insurance premium is the amount of money a person pays each month to keep their health insurance active. This payment helps cover doctor visits, tests, medicines, and hospital stays. It is different from other costs like copays or deductibles, which are paid when you use health care services. Understanding your premium helps you plan for health care expenses, especially during cancer treatment.

Healthy By Dr. Jen Candida Protocol is a complementary approach sometimes discussed in cancer care for symptom relief, nutrition support, or immune help. It is not a proven cancer treatment. Patients should talk with their care team about how it might fit their individual situation and avoid using it as a substitute for standard cancer therapies.

A healthy control is a person without the disease or condition being studied in a clinical research setting. Their test results or health data are used as a comparison to better understand changes seen in patients with cancer or other illnesses. For patients and caregivers, it’s important to ask your care team how the term applies to your specific situation rather than assuming it relates directly to diagnosis or treatment.

Heart cancer, also called cardiac sarcoma, is a very rare cancer that starts in the heart’s muscle or connective tissue. It can affect how the heart works and may cause symptoms like chest pain, shortness of breath, or irregular heartbeat. Because it is uncommon, diagnosis and treatment usually require specialized care from experts experienced in rare heart tumors.

Heart disease, also called cardiovascular disease, includes many conditions that affect the heart and blood vessels. Common types include coronary artery disease, heart failure, and stroke. Risk factors include age, smoking, high blood pressure, diabetes, unhealthy diet, and lack of exercise. Regular physical activity and healthy habits can help lower your risk and support heart health.

Heart rate, also called pulse, is the number of times your heart beats each minute. It can be felt at places where arteries are close to the skin, like your wrist or neck. A normal resting heart rate for most adults is between 60 and 100 beats per minute. Measuring heart rate helps doctors understand your overall health and how your body is responding to stress, illness, or treatment.

Heat-shock proteins (HSPs), also called stress proteins, are a group of proteins made by cells when they face stress like heat, infection, or lack of oxygen. They help protect and repair other proteins inside cells. Some HSPs, especially HSP90, are found at high levels in cancer cells and are being studied as targets for new cancer treatments.

Food Forensics / Heavy Metals Consumer Testing is a way to check foods, supplements, and related products for hidden toxins like heavy metals, pesticides, and additives. In cancer care, people may explore this testing to support nutrition, reduce symptoms, improve treatment tolerance, or simply to feel more in control. It is important to discuss this testing with your healthcare team before use during cancer treatment.

The Hedgehog signaling pathway is a natural process in the body that helps cells grow and develop, especially during early life. Changes in this pathway can sometimes lead to birth defects or cancer. If you see this term in your medical information, it’s important to ask your care team how it relates to your specific situation rather than assuming it means a diagnosis or treatment on its own.

Hedyotis Diffusa is a plant used in traditional Chinese medicine. It is sometimes used to support the immune system and may have anticancer effects. The name can refer to different but related plants, so it’s important to understand how it applies to your care. Always ask your healthcare team about its role in your treatment rather than assuming it is a diagnosis or a specific therapy.

Helical Computed Tomography, also called Spiral CT Scan, is a type of imaging test that uses a special x-ray machine to take detailed pictures of the inside of the body. The machine moves in a spiral path, allowing it to capture many images quickly and create clear, detailed views. This test helps doctors find small abnormal areas and is often used to diagnose, plan treatment, or check how well treatment is working.

Helical tomotherapy is a type of radiation therapy that uses a rotating machine to deliver precise doses of radiation to a tumor from many angles. The patient lies on a table that moves through a donut-shaped machine, which takes 3-D images to target the tumor while protecting nearby healthy tissue. It is also called tomotherapy. Patients should discuss with their care team how this treatment applies to their specific situation.

Helicobacter pylori (H. pylori) is a type of bacteria that infects the stomach lining. It can cause stomach inflammation, ulcers, and increase the risk of stomach cancer and certain lymphomas. Many people have this infection without symptoms. Risk factors include eating salted or smoked foods, smoking, being male, and having a family history of stomach cancer. Diagnosis and treatment can reduce cancer risk.

A helper T cell, also called a CD4-positive T lymphocyte, is a type of white blood cell that helps the immune system fight infections and diseases, including cancer. These cells activate other immune cells to work together in defending the body. They are important in understanding immune health and treatments like immunotherapy.

Hemagglutinin-neuraminidase is a protein found on the surface of certain viruses called paramyxoviruses, which include viruses like measles and mumps. This protein helps the virus attach to and infect human cells. In cancer care, infections with these viruses may affect treatment plans, especially if the immune system is weakened. Patients should discuss with their care team how this term relates to their health.

Hemangeol is a medicine containing propranolol hydrochloride, used to treat infantile hemangioma, a common benign blood vessel tumor in infants aged 5 weeks to 5 months. It may help shrink these vascular tumors. Propranolol is also used under other brand names to treat high blood pressure and other conditions. Hemangeol’s use in cancer care focuses on treating these noncancerous tumors in young infants.

Hemangiopericytoma is a rare type of soft-tissue tumor that starts in specialized cells called pericytes, which surround small blood vessels. It can occur in various parts of the body, including the brain coverings, legs, pelvis, and lungs. Surgery is the main treatment, but the tumor can come back or spread in some cases. Patients should discuss what this diagnosis means for their individual situation with their care team.

Hemangiosarcoma is a rare and aggressive cancer that starts in the cells lining blood vessels. It occurs mostly in dogs and often shows no symptoms until the tumor ruptures, causing severe bleeding. Understanding this term helps patients and caregivers recognize its role in diagnosis and treatment, but it’s important to discuss with the care team how it applies to each individual case.

Hematocrit (HCT) is a blood test that measures the percentage of your blood made up of red blood cells. It helps doctors check for conditions like anemia or dehydration and is often part of a complete blood count (CBC). In cancer care, hematocrit levels can show how treatments affect your blood and help monitor your overall health.

Hematogenous means something that starts in or spreads through the bloodstream. In infections, bacteria can travel through the blood to other parts of the body, causing new infections far from the original site. This is important in cancer care because infections can be serious, especially when the immune system is weakened. If you see this term, ask your care team how it relates to your situation.

Hematologic cancer, also called blood cancer, is a group of cancers that start in blood-forming tissues like the bone marrow or in immune system cells. Common types include leukemia, lymphoma, and multiple myeloma. These cancers affect how blood cells grow and work, which can impact the body’s ability to fight infections, carry oxygen, and control bleeding.

A hematologist is a doctor specially trained to diagnose and treat blood disorders. In children, a pediatric hematologist focuses on blood conditions like anemia, clotting problems, and blood cancers such as leukemia. Families may meet with this doctor during diagnosis, treatment, or follow-up to discuss test results and care plans tailored to young patients’ needs.

A hematoma is a collection of clotted blood that forms outside blood vessels, usually caused by injury or surgery. Most hematomas are small and heal on their own, but some may need medical treatment or surgery. If you see this term in your medical records, ask your care team what it means for your specific situation.

A Hematopathology Laboratory is a specialized lab that performs tests to help diagnose and treat diseases affecting the blood, bone marrow, and lymph system. If you see this term in your medical information, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment by itself.

Hematopoiesis is the natural process by which your body makes new blood cells. It usually happens in the bone marrow, the soft tissue inside your bones. Understanding hematopoiesis helps explain why blood tests are important and why some diseases affect blood cell production. Sometimes, blood cells are made outside the bone marrow, which can signal certain health conditions.

Hematopoietic growth factors are proteins that help the body make new blood cells. They are sometimes used during cancer treatment to reduce side effects like low blood counts caused by chemotherapy. If you see this term, it’s important to ask your care team how it relates to your treatment, as it is not a diagnosis or a treatment by itself.

Hematopoietic stem cells, also called blood stem cells, are early cells found mainly in the bone marrow and sometimes in the bloodstream. They can develop into all types of blood cells, including white blood cells, red blood cells, and platelets. These cells are important in cancer care because treatments like chemotherapy or radiation can affect blood cell production, and doctors may use stem cell transplants to help restore healthy blood cells.

A hematopoietic stem cell transplant (HSCT) is a medical procedure that replaces damaged or diseased blood-forming cells with healthy stem cells from bone marrow, blood, or umbilical cord blood. It is often used to treat certain blood cancers and other serious diseases. The transplant helps the body produce new, healthy blood cells after high-dose chemotherapy or radiation.

Hematopoietic tissue is the part of the body where new blood cells are made. It contains special cells called hematopoietic stem cells (HSCs) that can grow into different types of blood cells. These stem cells are important in treatments like bone marrow transplants, which are used for serious diseases. If you see this term, it’s best to ask your care team how it relates to your specific situation.

Hematoporphyrin derivative (HPD) is a mixture made from a chemical called hematoporphyrin. It is used in a cancer treatment called photodynamic therapy, where the drug is absorbed by tumor cells and then activated by light to help kill those cells. If you see this term, ask your care team how it relates to your specific situation rather than assuming it is a diagnosis or treatment plan.

Hematoxylin and eosin staining, often called H and E staining, is a common lab method that uses two dyes to color cells and tissues in a biopsy. This helps doctors see the shape and structure of cells under a microscope, which is important for identifying diseases like cancer. If you see this term in your medical reports, ask your care team what it means for your specific case.

Hematuria means having blood in the urine. It can be visible as red or brown urine or only seen under a microscope. Hematuria can have many causes, including infections, kidney stones, or cancer. If hematuria lasts, doctors assess the risk of urinary tract cancers to decide on further tests or care. Always ask your care team what hematuria means for you personally.

Heme is a part of molecules in the body that contains iron and helps carry oxygen in the blood. It is found in hemoglobin, the red pigment in red blood cells. Heme plays an important role in how cells use oxygen and energy. Understanding heme can help patients learn more about how their body works during cancer care.

Hemihyperplasia, also called hemihypertrophy, is a condition where one side of the body or part of it is larger than the other. Children with this condition have a higher risk of certain cancers, including Wilms tumor (a kidney cancer) and liver cancer. It’s important to understand this term in context and discuss with your care team what it means for you or your child.

Hemihypertrophy, also called hemihyperplasia, is a condition where one side of the body or part of it is larger than the other. This difference can be mild or more noticeable. Children with this condition have a higher risk of certain cancers, including Wilms tumor (a childhood kidney cancer) and liver cancer. It’s important to discuss what this means for your child with the care team.

Hemilaryngectomy is a surgery that removes one side of the larynx, or voice box. It is a type of partial laryngectomy used in cancer care to treat tumors while aiming to preserve as much voice and swallowing function as possible. Patients should discuss with their care team what this surgery means for their specific situation, including goals, risks, and recovery.

Hemizygous describes having only one copy of a gene instead of the usual two. For example, most males have one X and one Y chromosome, so they are hemizygous for genes on these chromosomes. This term is often seen in genetic reports but is not a diagnosis or treatment by itself. Patients should ask their care team how it applies to their specific situation.

Hemochromatosis, also called iron overload, is a condition where your body absorbs and stores too much iron. The extra iron builds up mainly in the liver, heart, and pancreas, which can cause organ damage, including liver disease and increase the risk of liver cancer. Symptoms may include tiredness, joint pain, stomach pain, and yellowing of the skin. Treatment can help manage iron levels and protect your organs.

Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the body’s tissues. In cancer care, hemoglobin levels are important because treatments like chemotherapy and radiation can lower red blood cell counts, leading to anemia. Monitoring hemoglobin helps your healthcare team understand how your treatment affects your blood and overall health.

Hemolysis is the breaking down of red blood cells, releasing their contents into the blood. It can happen due to various causes like infections, genetic conditions, or certain medicines. Hemolysis may affect lab tests and can sometimes lead to anemia or increase infection risk. If you see this term in your medical records, ask your care team what it means for your specific situation.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and serious disorder where certain white blood cells become overactive and attack the body’s own tissues. It can be inherited or triggered by infections, immune problems, or cancer. HLH causes inflammation and damage in organs like the liver, spleen, and skin. Treatment options include medicines like emapalumab (Gamifant) that help calm the immune system when standard therapies don’t work.

Hemophilia is a rare inherited disorder where the blood does not clot properly due to low levels of certain clotting proteins. This can cause easy bruising, bleeding into joints or muscles, and serious bleeding after injuries or surgery. It mainly affects males and is diagnosed through blood tests and family history. Treatment involves replacing the missing clotting factors to help blood clot normally.

Hemoptysis means coughing up blood or blood-stained mucus from the lungs, windpipe, or airways. It can happen with infections, lung cancer, or other lung problems. Sometimes blood from the nose or sinuses may look like hemoptysis but comes from a different source. If you notice blood when coughing or spitting, it’s important to talk with your care team to understand what it means for you.

A hemorrhage is when blood escapes from damaged blood vessels, causing bleeding that can be inside the body or visible outside. In cancer care, hemorrhage may happen near tumors or after surgery, and it often requires careful attention. If you see this term in your medical records or hear it from your care team, it’s important to ask how it applies to your specific situation rather than assuming it means a particular diagnosis or treatment.

A hemorrhagic cerebrovascular accident, also called a hemorrhagic stroke, happens when a blood vessel in or on the brain breaks or leaks, causing bleeding. This bleeding can increase pressure and damage brain tissue. Common causes include high blood pressure, aneurysms, head injuries, or bleeding disorders. If you see this term, ask your care team how it relates to your situation rather than assuming it is a diagnosis or treatment plan.

Hemorrhagic cystitis is a condition where the bladder lining becomes inflamed and bleeds, causing blood in the urine. It can cause pain or burning during urination, frequent urges to urinate, and sometimes loss of bladder control. Causes include certain anticancer drugs, radiation therapy, infections, or exposure to chemicals. If you see this term in your care, ask your healthcare team how it applies to your situation.

A hemorrhagic stroke happens when a blood vessel in the brain breaks or leaks, causing bleeding inside or around the brain. This bleeding can increase pressure and damage brain cells. It is a medical emergency that needs quick treatment. Hemorrhagic stroke may also be called hemorrhagic cerebrovascular accident. Recognizing symptoms early and calling 911 can save lives and improve recovery.

Hemorrhoids are swollen or enlarged blood vessels near the anus or lower rectum. They can cause symptoms like pain, itching, swelling, or bright red bleeding during bowel movements. Many people find relief with home treatments such as warm baths, creams, and dietary changes. If symptoms last more than a week or if there is rectal bleeding, it’s important to see a healthcare provider to rule out other causes.

Hemp, also called industrial hemp, is a type of Cannabis sativa plant grown for its fiber, seeds, and oil. It contains very low levels of THC, the part of marijuana that causes a “high.” Hemp is used to make many products and is the source of cannabidiol (CBD), a chemical studied for managing symptoms related to cancer and its treatments. CBD is not approved to treat cancer itself, so patients should discuss its use with their healthcare team.

Heparin is a medicine that helps prevent blood clots by slowing their formation. It is often used to reduce the risk of deep vein thrombosis, pulmonary embolism, stroke, or heart attack. In cancer care, heparin and related drugs may be used especially around surgery to lower the chance of dangerous clots. Patients should always ask their care team how heparin applies to their specific situation rather than assuming it means a diagnosis or treatment on its own.

A hepatectomy is a major surgery to remove all or part of the liver. It is often done to treat liver tumors, including cancer that has spread from other organs, or to remove other liver problems like gallstones or cysts. Because it is a complex procedure, it is important to understand how it applies to your specific situation by talking with your healthcare team.

Hepatic means relating to the liver, a vital organ that processes nutrients, filters blood, and helps with digestion. In cancer care, the term hepatic often appears when discussing liver function, blood vessels, or treatments targeting the liver. It’s important to understand hepatic in context and ask your care team how it applies to your specific situation.

Hepatic arterial infusion (HAI) is a medical procedure that delivers chemotherapy directly to the liver through a catheter placed in the hepatic artery. It is mainly used to treat liver tumors, especially liver metastases from colorectal cancer. This targeted approach aims to reach cancer cells in the liver more directly than standard chemotherapy. Patients should discuss with their care team how HAI might apply to their specific treatment plan.

Hepatic arterial occlusion means a blockage of blood flow in the hepatic artery, which supplies blood to the liver. Sometimes doctors cause this blockage on purpose during treatments like chemotherapy to help kill liver cancer cells. If you see this term, it’s important to ask your care team how it relates to your specific situation rather than assuming it is a diagnosis or treatment by itself.

The hepatic artery is the main blood vessel that carries oxygen-rich blood to the liver. In cancer care, it is important because liver tumors often get their blood supply from this artery. Treatments like hepatic arterial infusion deliver chemotherapy directly through the hepatic artery to target liver tumors more precisely. Patients should always ask their care team how this term relates to their specific situation.

The hepatic portal vein, also called the portal vein, is a large blood vessel that carries nutrient-rich blood from the intestines, spleen, pancreas, and gallbladder to the liver. It plays a key role in processing substances absorbed from digestion before they enter the rest of the body. Understanding this term can help patients and caregivers better follow liver-related cancer reports or treatments.

Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome, is a condition where small veins in the liver become blocked. This can reduce blood flow and cause liver damage. It often happens after a stem cell transplant, especially in people with kidney or lung problems. Defibrotide sodium (brand name Defitelio) is a medicine approved to treat this condition by helping improve blood flow inside the liver.

Hepatitis is inflammation of the liver that can cause symptoms like fever, nausea, and yellowing of the skin. It can be caused by viruses, heavy alcohol use, or other factors. Some types of hepatitis go away on their own, while others can lead to serious liver problems like scarring, liver failure, or cancer. Diagnosis usually involves blood tests and physical exams, and treatments depend on the type and severity of hepatitis.

The hepatitis A vaccine helps prevent infection with the hepatitis A virus, which can cause serious liver illness. It works by teaching the immune system to fight the virus using a weakened or inactivated form of it. Patients and caregivers should discuss with their care team how this vaccine fits into their personal health plan rather than assuming it is a treatment or diagnosis on its own.

Hepatitis A virus is a virus that causes a serious liver infection. It spreads mainly through contact with infected stool, often by eating food handled by someone who did not wash their hands. Symptoms can include jaundice (yellowing of skin and eyes), dark urine, fever, and flu-like feelings. Understanding this virus is important, especially when mentioned in medical records or care plans, so patients should ask their healthcare team how it relates to their situation.

Hepatitis B virus (HBV) is a virus that infects the liver. Many people with HBV have no symptoms, but long-term infection can cause serious liver problems like scarring (cirrhosis) and liver cancer. HBV spreads through blood and body fluids, and a vaccine is available to help prevent infection and related liver cancer.

Hepatitis C virus (HCV) is a virus that infects the liver and can cause inflammation called hepatitis. Many people have no symptoms, but long-term infection can lead to serious liver problems such as scarring (cirrhosis) and liver cancer. HCV spreads mainly through contact with infected blood, such as sharing needles. Early diagnosis and treatment can often cure the infection and prevent complications.

Hepatitis D Virus (also called hepatitis delta virus) is a virus that infects the liver and only occurs alongside hepatitis B virus (HBV). It spreads through blood or sexual contact and can make liver inflammation caused by hepatitis B worse. If you see this term in medical information, ask your care team what it means for your health rather than assuming it is a diagnosis or treatment plan.

Hepatitis Delta Virus (also called Hepatitis D Virus) is a virus that infects the liver but only occurs in people who already have hepatitis B virus. It spreads through blood or sexual contact and can make liver inflammation caused by hepatitis B more severe. If you see this term in medical information, ask your care team what it means for your health rather than assuming it is a diagnosis or treatment plan.

Hepatitis E virus (HEV) is a virus that causes inflammation of the liver, known as hepatitis E. It spreads mainly through contaminated food or water. There are eight types of HEV found in different parts of the world, including Asia, Africa, Europe, and North America. Understanding HEV is important for liver health and overall care, especially in people with weakened immune systems or liver conditions.

Hepatitis G Virus is a virus that can be found in people with hepatitis, which means inflammation of the liver. It spreads through blood or sexual contact and can also be passed from an infected mother to her baby. If you see this term, it’s important to ask your healthcare team what it means for your specific health situation rather than assuming it is a diagnosis or treatment plan.

Hepatobiliary refers to the liver, bile ducts, and gallbladder—the organs that make, store, and move bile to help digest fats. In cancer care, the term often appears when discussing tumors or conditions affecting these parts. It’s important to understand hepatobiliary in context and ask your care team what it means for your specific situation, rather than treating it as a diagnosis or treatment by itself.

Hepatoblastoma is a rare type of liver cancer that mainly affects infants and young children. It usually appears as a lump in the abdomen and may be linked to certain genetic conditions. Understanding hepatoblastoma helps patients and caregivers recognize its importance in cancer care and the need to discuss individual risks and treatment options with healthcare providers.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. It starts in liver cells called hepatocytes. Risk factors include chronic hepatitis B or C infections, heavy alcohol use, cirrhosis, and certain liver diseases. HCC often develops in people with long-term liver damage and may be hard to treat if surgery is not an option.

A hepatocyte is a type of cell that makes up most of the liver. These cells perform many important jobs, including helping the body process nutrients, make proteins, and remove toxins. In cancer care, understanding hepatocytes can help you follow discussions about liver health and treatments that target proteins related to these cells.

Hepatolenticular Degeneration, also called Wilson Disease, is a rare inherited disorder where too much copper builds up in the body. This extra copper mainly affects the liver, brain, and eyes. Symptoms can include yellowing of the skin and eyes, swelling in the abdomen and legs, fatigue, speech and swallowing problems, uncontrolled movements, and mood changes like anxiety or depression.

Hepatoma is a medical term that refers to a tumor in the liver. Patients and caregivers may encounter this word when reading about cancer, test results, or treatment options. It’s important to understand the term in context and ask your healthcare team what it means for your specific situation, rather than assuming it is a complete diagnosis or treatment plan on its own.

Hepatomegaly means an enlarged liver. You might see this term when reading about cancer, test results, or symptoms. It is not a diagnosis by itself but a sign that can have many causes. If you come across this word, it’s important to ask your care team what it means for your specific situation rather than assuming anything on your own.

Hepzato is a brand name for melphalan hydrochloride, a chemotherapy drug used as a liver-directed treatment for adults with uveal melanoma that has spread to the liver but cannot be removed by surgery. It is given as an infusion directly into an artery leading to the liver. Hepzato helps stop cancer cells from growing by damaging their DNA. Patients should discuss with their care team how this treatment fits their individual plan.

HER1, also known as EGFR or epidermal growth factor receptor, is a protein found on some cells that helps control cell growth and survival. Changes in the EGFR gene can cause cancer cells to grow faster. Some cancer treatments target HER1/EGFR to help slow or stop tumor growth. If you see this term in your care, ask your healthcare team what it means for your specific situation.

The HER1 gene, also called the EGFR gene, ERBB1 gene, or epidermal growth factor receptor gene, makes a protein that helps control how cells grow and survive. Changes in this gene can cause some cancers, especially certain lung cancers, to grow faster. Testing for changes in the HER1 gene in tumor tissue can help doctors choose treatments that target these changes and may slow cancer growth.

HER2 is a protein found on some cells that helps them grow. Some cancer cells, especially in breast cancer, may have more HER2 than usual. This can cause the cancer to grow faster and spread. Testing for HER2 helps doctors understand the cancer better and decide on the best treatment. HER2 may also be called c-erbB-2, HER2/neu, or human epidermal growth factor receptor 2.

HER2 Negative means cancer cells have little or no HER2 protein on their surface. HER2 is a protein that helps control cell growth. Cancers that are HER2 negative often grow more slowly and may be less likely to spread than HER2 positive cancers. This term is commonly used in breast cancer and helps guide treatment decisions.

HER2 Positive means cancer cells have more than the usual amount of a protein called HER2 on their surface. This protein helps control cell growth. When there’s too much HER2, cancer cells may grow faster and spread more easily. Knowing if a cancer is HER2 positive helps doctors choose treatments that specifically target these cells, often improving care for cancers like breast, stomach, and others.

A HER2 test is a lab test that measures the amount of HER2 protein or gene copies on cancer cells. HER2 is a protein that helps control cell growth. Some cancers, especially breast cancer, may have too much HER2, which can make cancer grow faster. Knowing HER2 status helps doctors plan treatment, including targeted therapies that focus on HER2-positive cancer cells.

HER2-low breast cancer is a type of breast cancer where cancer cells have a small amount of a protein called HER2 on their surface. These cancers usually do not have extra copies of the HER2 gene. While traditionally treated like HER2-negative breast cancer, newer targeted drugs have shown effectiveness for HER2-low breast cancer. Patients should discuss what this means for their care with their healthcare team.

HER2/Neu is a protein found on some cells that helps control normal growth. Some cancers, like breast and ovarian cancer, may have too much HER2, which can make cancer cells grow faster and spread. Testing for HER2 helps doctors understand the cancer and choose treatments that target these cells. It may also appear under related names such as C-Erbb-2, HER2, Human EGF Receptor 2, And Human Epidermal Growth Factor Receptor 2.

The Her2/Neu Test, also called the HER2 test or human epidermal growth factor receptor 2 test, is a lab test that measures the amount of HER2 protein or gene copies on cancer cells. Some cancers, especially breast cancer, may have extra HER2, which can make cancer grow faster. Knowing HER2 status helps doctors plan treatment, including targeted therapies that focus on HER2-positive cancer cells.

Herba Scutellaria Barbatae is an herb used in traditional Chinese medicine that may have anticancer effects. It is sometimes included in herbal drinks and supplements. If you see this term in your medical records or discussions, it’s important to ask your care team how it relates to your specific situation rather than assuming it is a diagnosis or treatment recommendation.

Herbal products come from plants and are sometimes used alongside cancer care. Patients should not assume herbal mixtures like ACAPHA can replace standard treatments or that they are always safe. It’s important to talk with your healthcare team about any herbal use to avoid risks and ensure it fits with your care plan.

A herbal cigarette is a cigarette made from a mix of herbs and plant materials instead of tobacco or nicotine. While often marketed as tobacco-free or nicotine-free, herbal cigarettes still produce harmful chemicals similar to regular cigarettes. Patients and caregivers should discuss any use or mention of herbal cigarettes with their healthcare team to understand what it means for their care.

Herbal medicine uses parts of plants like roots, leaves, or flowers to support health or treat illness. Some herbal products, including those from traditional systems like Ayurveda, may interact with cancer treatments or cause side effects. It’s important for patients and caregivers to talk with their healthcare team before using herbal medicines to ensure safety and avoid interfering with standard cancer care.

Herbal supplements are products made from plants that some people use to support health or manage symptoms during cancer care. While some herbs like Aloe are known for soothing skin, herbal supplements are not proven cancer treatments. Their safety and effects can vary, so it’s important to talk with your healthcare team before using any herbal product during cancer treatment.

Herbicides are chemicals used to kill unwanted plants, often called weeds. In cancer care, discussions about herbicides may arise when testing for contaminants in food, water, or soil, especially through programs like CWC Labs Clean Food and Contaminant Testing. This testing is sometimes explored by patients interested in nutrition support or reducing exposure to substances during treatment, but it is not a cancer treatment itself.

Herceptin is a targeted therapy drug used to treat certain breast and stomach cancers that have high levels of the HER2 protein. It is a monoclonal antibody that helps the immune system attack cancer cells. Herceptin may be known by other names like trastuzumab, Hercessi, Herzuma, Kanjinti, Ogivri, Ontruzant, and Trazimera. It is given by injection and is often combined with chemotherapy.

Herceptin Hylecta is a targeted therapy drug combining trastuzumab and hyaluronidase. It treats certain HER2-positive breast cancers by blocking cancer cell growth and helping the immune system attack these cells. Unlike trastuzumab alone, it is given as a quick injection under the skin rather than a longer infusion. It may also appear under related names such as Trastuzumab, Hyaluronidase.

Hercessi is a brand name for trastuzumab, a targeted therapy drug used to treat certain breast and stomach cancers that have high levels of the HER2 protein. It works by attaching to HER2 on cancer cells, helping the immune system attack them. Hercessi is given by injection and may be known by other names like Herceptin, Herzuma, Kanjinti, Ogivri, Ontruzant, and Trazimera.

Herd immunity, also called community immunity, happens when many people in a community are vaccinated against a contagious disease. This helps protect those who cannot get vaccines, such as some cancer patients with weakened immune systems, by making it harder for the disease to spread. While it lowers the overall risk of infection, herd immunity does not guarantee complete protection for everyone.

Hereditary means that certain genetic changes are passed down from parents to children, which can increase the risk of some cancers like breast, ovarian, and colorectal cancer. These inherited changes, such as in the BRCA1 and BRCA2 genes, may lead to hereditary cancer syndromes. Knowing if cancer is hereditary can help guide screening and treatment decisions.

Hereditary Breast and Ovarian Cancer Syndrome (HBOC) is an inherited condition that raises the risk of breast and ovarian cancers, often at younger ages. It is most often caused by changes in the BRCA1 or BRCA2 genes. People with HBOC may also have higher chances of other cancers like pancreatic, prostate, and melanoma. Genetic testing and counseling can help identify and manage this risk.

A hereditary cancer syndrome is an inherited condition caused by changes in certain genes that increase the risk of developing specific types of cancer. These syndromes often run in families and may cause cancer to appear at younger ages or in multiple family members. People with a personal or family history suggesting such a syndrome should talk with their doctor or a genetic counselor about genetic testing.

Hereditary Diffuse Gastric Cancer (HDGC), also called Familial Diffuse Gastric Cancer, is a rare inherited condition that raises the risk of a specific type of stomach cancer affecting the stomach lining. It is caused by inherited changes in the CDH1 gene. Women with HDGC also have a higher chance of developing a certain type of breast cancer that starts in the milk glands.

Hereditary hemochromatosis is an inherited condition where the body absorbs too much iron from food. This extra iron builds up in organs like the liver, heart, and pancreas, which can cause damage over time. People with this condition have a higher risk of liver problems, including liver cancer. Early diagnosis and care can help manage the condition and reduce complications.

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare inherited condition caused by changes in the FH gene. It leads to non-cancerous skin and uterine tumors and increases the risk of a specific type of kidney cancer. Symptoms usually appear in young adulthood. Knowing about HLRCC can help with early detection and management of related health risks.

Hereditary Nonpolyposis Colorectal Cancer (HNPCC), also called Lynch syndrome, is an inherited condition that increases the risk of colon cancer and several other cancers. It is caused by changes in genes that help fix DNA mistakes. Testing tumor tissue or blood can help identify if someone has this condition, which can guide care and inform family members about their risks.

Hereditary Papillary Renal Cancer (HPRC) is a rare inherited condition that raises the risk of developing type 1 papillary kidney cancer. This cancer starts in the lining of small tubes inside the kidneys, which help filter blood and make urine. HPRC often affects both kidneys and may cause multiple tumors. It is linked to changes in the MET gene and is part of hereditary cancer syndromes.

Hereditary Papillary Renal Carcinoma (HPRC) is a rare inherited condition that increases the risk of developing type 1 papillary kidney cancer. This cancer starts in the small tubes inside the kidneys that filter blood and make urine. HPRC often affects both kidneys and may cause multiple tumors. It is linked to changes in the MET gene and is part of hereditary cancer syndromes.

Hereditary paraganglioma-pheochromocytoma syndrome is a rare genetic condition where people develop multiple tumors called paragangliomas, often near nerves or blood vessels. These tumors are usually not cancer but can sometimes become cancerous. People with this syndrome may also have a higher risk of certain cancers like kidney and thyroid cancer. It’s important to discuss what this means personally with your care team.

Hereditary predisposition, also called genetic susceptibility or inherited predisposition, means having inherited gene changes that increase the chance of developing certain diseases, including some cancers. It is not a diagnosis but a way to understand inherited risks. Genetic testing can identify these changes, but results should be discussed with your care team to understand what they mean for you personally.

A hereditary syndrome is a condition caused by gene changes passed down from parents to children. Some hereditary syndromes increase the risk of certain cancers, including kidney cancer. People with family histories of cancer, early-onset cancer, or multiple tumors may be referred for genetic counseling and testing to understand their risks and guide care.

Heritable means a trait or risk that can be passed from a parent to a child through genes. In cancer care, some cancers have heritable forms where inherited gene changes increase risk. Genetic testing of blood or saliva can help identify these inherited changes. It’s important to understand heritable risk in context and discuss with your care team how it applies to you or your family.

Heritage refers to a person’s ancestry or background, which can affect their health risks, especially inherited risks for cancer. Knowing your heritage helps your care team understand why they might focus on family history or genetic testing, rather than just current symptoms or test results. It’s important to ask your care team how your heritage relates to your health, rather than assuming it means a diagnosis or treatment plan.

A hernia happens when an internal organ or tissue pushes through a weak spot or tear in the muscle or tissue that normally holds it in place. Most hernias occur in the abdomen and can cause a visible bulge, discomfort, or pain. Hernias may need surgery to prevent complications like bowel blockage or strangulation. If you hear this term, ask your care team how it relates to your health.

Heroin, also called diacetylmorphine or diamorphine, is an opioid drug made from morphine found in the opium poppy. It is illegal in the U.S. and is mainly used recreationally for its strong euphoric effects. Heroin is highly addictive and can cause serious health problems, including overdose. In some cases, diamorphine is used medically to help treat opioid addiction under strict supervision.

Herpes Simplex Virus (HSV) is a common virus that causes infections like cold sores and genital sores. It includes two types: HSV-1, often linked to cold sores around the mouth, and HSV-2, usually causing genital sores. HSV infections are widespread and can be contagious even without visible symptoms. Understanding HSV in your medical reports is important, and you should ask your care team how it relates to your health.

Herpes zoster, also called shingles, is a viral infection caused by the varicella-zoster virus—the same virus that causes chickenpox. It usually causes a painful rash with blisters on one side of the body or face. The virus can reactivate years after chickenpox, especially in older adults or people with weakened immune systems. Sometimes, symptoms occur without the rash, a condition called zoster sine herpete.

Herpesviruses are a family of viruses that can cause common infections like cold sores, chickenpox, and shingles. People with weakened immune systems, such as those undergoing cancer treatment, are more vulnerable to these infections. Some medicines, like brivudine, are being studied to help prevent or treat herpesvirus infections in these patients, but they are not yet standard treatments.

Herzuma is a brand name for trastuzumab, a targeted therapy drug used to treat certain breast and stomach cancers that have high levels of the HER2 protein. It works by attaching to HER2 on cancer cells, helping the immune system attack them. Herzuma is given by injection and is often combined with chemotherapy. It may also be known by other names like Herceptin, Hercessi, Kanjinti, Ogivri, Ontruzant, and Trazimera.

Heterocyclic amines (HCAs) are chemicals that form when meat, poultry, or fish is cooked at high temperatures, such as frying, grilling, or barbecuing. Laboratory studies show HCAs can cause changes in DNA that might increase cancer risk. HCAs are one of several chemicals studied for their possible link to cancer, especially when meats are cooked well done or over open flames.

Heterogeneous means made up of parts that are different from each other. In cancer, it refers to how tumors can have many different types of cells or genetic changes within them. This variety can affect diagnosis and treatment. It’s important to ask your care team what heterogeneous means for your specific situation rather than assuming it is a diagnosis or treatment plan.

Heterogeneously dense breast tissue is a type of breast tissue seen on mammograms, where large areas of dense fibrous and glandular tissue mix with some fatty tissue. This density can make it harder to spot tumors on mammograms. About 40% of women have this breast tissue type. It’s important to discuss what this means personally with your care team rather than treating it as a diagnosis or treatment plan.

Heterogenic (also called heterogenous) means something is made up of parts from different sources or types. In cancer care, this word often describes how cells or tissues can vary within a tumor or between samples. For patients and caregivers, it’s important to understand this term in context and ask your care team what it means for your specific situation, rather than assuming it is a diagnosis or treatment plan.

Heterogenous (also called heterogenic) means made up of parts from different sources or types. In cancer care, it often describes how cells or tissues within a tumor can vary. It’s important to understand this term in context and ask your care team what it means for your specific situation, rather than assuming it is a diagnosis or treatment plan.

A heterozygous genotype means a person has two different versions of the same gene—one inherited from each parent. One gene copy may be normal while the other has a change or mutation. This term describes a genetic detail, not a diagnosis or treatment plan. Patients should ask their care team how it relates to their specific health situation.

Hexyl 5-Aminolevulinate is a substance used to help find and kill tumor cells. It works by entering tumor cells and becoming active when exposed to a special light, causing the cells to glow and die. Patients should discuss with their care team how this substance might be part of their diagnosis or treatment, rather than assuming it means a specific plan or outcome.

HGS-ETR1, also called mapatumumab or anti-TRAIL R1-mAb, is an experimental laboratory-made antibody designed to attach to a protein called TRAIL R1 found on some cancer cells. It is being studied in clinical trials to see if it can help kill tumor cells by encouraging them to self-destruct. This treatment is not yet standard and is still under research.

HGS-ETR2, also called lexatumumab, is an experimental lab-made protein designed to attach to a protein called TRAIL-R2 on some cancer cells. By binding to this protein, it may help kill tumor cells. It is still being studied and is not yet part of standard cancer treatment. It may also appear under related names such as Anti-TRAIL R2 Mab HGS-ETR2, Lexatumumab.

The Department of Health and Human Services (HHS), also called DHHS, is a U.S. government agency that works to protect public health. It oversees programs related to medical research, food and drug safety, health insurance, and disease prevention. You may hear about HHS in health news, research studies, or cancer prevention advice.

HHV stands for human herpesvirus, a group of viruses that commonly infect people. There are nine types, including herpes simplex viruses (HSV-1 and HSV-2) that cause cold sores and genital herpes, varicella zoster virus causing chickenpox and shingles, Epstein-Barr virus linked to mononucleosis and some cancers, and human cytomegalovirus. HHV infections are common and may be mentioned in cancer care when immune systems are weakened.

HHV8, also known as human herpesvirus 8 or Kaposi sarcoma-associated herpesvirus (KSHV), is a virus linked to certain rare cancers. It can cause Kaposi sarcoma, a cancer that forms lesions on the skin and other tissues, and some types of lymphoma, which are cancers of the immune system. Understanding HHV8 is important in specific cancer diagnoses, but seeing the term alone is not a diagnosis or treatment plan.

HIF, or Hypoxia-Inducible Factor, is a protein that helps cells respond when oxygen levels are low. Some cancer cells may produce more HIF, which can help them grow and spread. If you see this term in your medical information, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

HIFU, or High-Intensity Focused Ultrasound Therapy, is a treatment being studied for prostate cancer and other diseases. It uses high-energy sound waves aimed at abnormal tissue to create heat that kills those cells. HIFU is non-invasive, meaning it does not require surgery, and may be mentioned under different names. Patients should always ask their care team how HIFU applies to their specific situation.

A High Antioxidant Diet is a nutrition approach discussed in cancer care for its potential to support nutrition, reduce inflammation, aid digestion, boost immune health, and help patients tolerate treatments. It is sometimes considered as part of supportive care or alternative approaches, but its safety and effectiveness should always be reviewed with healthcare providers familiar with the patient’s cancer and overall health.

High blood pressure, also called hypertension, means the force of blood pushing against your artery walls is too high. It often has no symptoms but can increase the risk of heart problems, stroke, kidney damage, and other health issues. Many adults have high blood pressure without knowing it. It is diagnosed by measuring two numbers: systolic (pressure when the heart beats) and diastolic (pressure when the heart rests).

High blood sugar, also called hyperglycemia, means having more glucose (a type of sugar) in your blood than normal. It can happen with diabetes or other health conditions. High blood sugar may cause symptoms like increased thirst, frequent urination, and fatigue. Managing blood sugar is important for overall health and during cancer care. If you see this term in your medical records, ask your care team what it means for you.

A High Cruciferous Vegetable Diet involves eating large amounts of vegetables like broccoli, cauliflower, and kale. It is discussed in cancer care for its possible effects on nutrition, inflammation, digestion, immune health, and how well patients tolerate treatment. While some people explore it as part of cancer prevention or support, it should be used carefully and always discussed with healthcare providers.

A high fiber diet includes foods rich in dietary fiber, such as fruits, vegetables, whole grains, nuts, and legumes. It is often discussed in cancer care for supporting digestion, immune health, inflammation control, and treatment tolerance. While generally linked to better overall health, cancer patients should consult their care team before making major diet changes.

High grade describes cancer cells that look more abnormal under a microscope and tend to grow and spread faster than low-grade cells. High-grade cancers often need treatment sooner or more intensive treatment. For patients and caregivers, it’s important to understand this term in the context of the individual diagnosis and to ask the care team what it means for their specific situation.

Cesium Chloride, also called High pH Therapy, is an alternative treatment some people use for advanced cancer. It involves taking cesium chloride supplements to try to change the acidity (pH) inside cancer cells. However, there is no reliable scientific evidence that it works, and it can cause serious heart problems. Patients should always discuss this therapy with their healthcare team before use.

High Vitamin C Nutrition Protocols are diet or nutrition approaches involving increased vitamin C intake, discussed in cancer care for supporting nutrition, metabolism, inflammation, digestion, immune health, and treatment tolerance. These protocols may be considered as supportive care or alternative approaches but should be reviewed carefully with healthcare providers to understand their role and safety in each patient’s cancer treatment plan.

A High-Calorie Cachexia Support Diet helps cancer patients who are losing weight unintentionally and experiencing muscle loss. It focuses on eating calorie-rich, high-protein foods, using nutrition supplements, managing symptoms, and working with a dietitian. This approach aims to maintain strength and help patients tolerate cancer treatments better. It’s important to discuss with your care team how this diet fits your individual needs.

High-dose chemotherapy is a cancer treatment that uses stronger doses of chemotherapy drugs to kill cancer cells. Because these high doses can harm the bone marrow, patients often receive a stem cell transplant afterward to help their blood and immune system recover. This approach is used for some cancers, including certain blood cancers and testicular cancer, especially when standard treatments are not enough.

High-Dose Intravenous Vitamin C (IVC) is a method of giving vitamin C directly into the bloodstream at much higher levels than oral supplements. It is sometimes discussed in cancer care for supporting nutrition, metabolism, immune health, inflammation, digestion, and helping patients tolerate treatment. However, it is not an FDA-approved cancer treatment and is considered an alternative or supportive approach rather than a standard therapy.

High-Dose Intravenous Vitamin C (IVC) is a way of giving vitamin C directly into the bloodstream at much higher levels than oral supplements. It is sometimes used in cancer care to support nutrition, metabolism, immune health, inflammation, digestion, and help patients tolerate treatments. However, it is not an FDA-approved cancer treatment and is considered experimental or supportive rather than standard therapy.

High-dose radiation (HDR) is a type of radiation therapy that delivers a larger amount of radiation directly to a tumor in fewer treatments. It aims to kill more cancer cells while protecting healthy tissue nearby. HDR is carefully planned and targeted to improve treatment effectiveness and may be part of your cancer care plan.

High-Dose Vitamins, also called Megavitamin Therapy, refers to taking vitamins in amounts much larger than usual. In cancer care, people may use or consider these vitamins for various reasons, such as trying to support nutrition, ease symptoms, improve recovery, or boost the immune system. It is important to talk with your healthcare team before starting high-dose vitamins, as they can affect cancer treatments and overall health.

High-Dose Vitamins, also called Megavitamin Therapy, means taking vitamins in amounts much larger than usual. In cancer care, people may use these vitamins to support nutrition, ease symptoms, improve recovery, or boost the immune system. It’s important to talk with your healthcare team before starting, as high doses can affect cancer treatments and overall health.

High-Dose-Rate Remote Brachytherapy is a type of internal radiation treatment where temporary radioactive sources deliver high doses of radiation in short bursts. Also called high-dose-rate remote radiation therapy or remote brachytherapy, it involves placing radiation inside or near a tumor for brief sessions. Patients should ask their care team how this treatment applies to their specific situation rather than assuming the term alone describes a diagnosis or treatment plan.

High-Dose-Rate Remote Radiation Therapy, also called high-dose-rate remote brachytherapy or remote brachytherapy, is a type of internal radiation treatment. It uses temporary radioactive sources placed inside or near a tumor to deliver short, intense bursts of radiation during each treatment session. The radioactive material is removed between sessions, helping target cancer while limiting exposure to healthy tissue. Patients should ask their care team how this treatment applies to their specific situation.

High-Energy Photon Therapy is a type of radiation treatment that uses powerful light energy called photons. These photons can reach deep tumors while reducing radiation exposure to the skin and other surface tissues. Patients should discuss with their care team how this therapy fits their specific situation, as the term alone does not describe a diagnosis or treatment plan.

High-Grade DCIS (also called Grade III DCIS or high-grade ductal carcinoma in situ) is a condition where abnormal breast cells that look very different from normal cells are found inside the lining of a breast duct. These cells have not spread outside the duct. High-grade DCIS tends to grow faster and is more likely to come back or develop into invasive breast cancer than lower-grade DCIS.

High-Grade Ductal Carcinoma In Situ (DCIS), also called Grade III DCIS or high-grade DCIS, is a condition where abnormal breast cells are found inside the lining of a breast duct. These cells look very different from normal cells but have not spread outside the duct. High-grade DCIS tends to grow faster and may be more likely to return or develop into invasive breast cancer compared to lower grades.

High-grade lymphoma, also called aggressive or intermediate-grade lymphoma, is a fast-growing cancer of the lymphatic system. It often causes noticeable symptoms and usually needs prompt treatment. The term describes how quickly the lymphoma grows and spreads, not the final diagnosis or treatment outcome. Patients should ask their care team what this means for their specific situation.

High-Grade Squamous Intraepithelial Lesion (HSIL) is a term used when cervical cells look moderately or severely abnormal under a microscope. These changes are more serious than mild abnormalities and have a higher chance of developing into cervical cancer if not treated. HSIL often appears in Pap test results and usually leads to further tests or treatment to prevent cancer.

High-Intensity Focused Ultrasound Therapy (HIFU) is a non-invasive procedure that uses high-energy sound waves to heat and destroy abnormal cells or tissue in the body. It is being studied mainly for prostate cancer and some other cancers. HIFU does not involve surgery and aims to target only the affected area, potentially reducing side effects. Patients should discuss with their care team how HIFU might apply to their specific situation.

A high-protein cancer support diet is a nutrition plan designed to help people with cancer maintain or rebuild muscle, support healing, and keep strength during treatment. It uses protein-rich foods, supplements, and guidance from dietitians to address challenges like poor appetite, weight loss, or treatment side effects. This diet supports recovery and overall well-being but is tailored to each person’s needs and health conditions.

High-resolution micro-ultrasound is a type of imaging that uses high-energy sound waves to create detailed pictures of the prostate and nearby tissues. It helps doctors spot suspicious areas and guide biopsies to collect tissue samples. This tool may be used to diagnose prostate cancer, monitor its growth, and plan treatment. Patients should discuss with their care team how this test fits their individual situation.

High-risk cancer refers to cancer that has a greater chance of coming back after treatment or spreading to other parts of the body. This term helps describe how serious or aggressive a cancer might be, but its exact meaning can vary depending on the type of cancer and the situation. Understanding this term can help patients and caregivers better follow treatment plans and discussions with their care team.

High-risk HPV (human papillomavirus) is a group of virus types that can infect the cells of the cervix and other body areas. Some types, especially HPV 16 and 18, can cause cell changes that may lead to cancer over time if not found and treated. High-risk HPV is common and usually spreads through intimate skin-to-skin contact, often during sexual activity. Vaccines and screening tests help prevent and detect problems early.

High-risk human papillomavirus (HPV) is a group of common viruses spread mainly through sexual contact. Some types can cause long-lasting infections that may lead to cell changes and cancers over time, especially cervical cancer. HPV types 16 and 18 cause most HPV-related cancers. Vaccines can help protect against these high-risk types and reduce cancer risk.

High-selenium Brassica juncea is a type of Indian mustard plant grown with extra selenium, a mineral that may help stop tumor growth. It is being studied for its potential role in cancer treatment. Patients should discuss with their care team how this term relates to their care, rather than seeing it as a direct treatment or diagnosis.

Vibe or High-Vibration Wellness is a supportive approach some people explore during cancer care. It involves ideas about energy, thought patterns, nutrition, and lifestyle aimed at improving well-being, stress, symptom relief, and recovery. While it is not a proven cancer treatment, patients may use it to support quality of life or complement medical care. Always discuss with your healthcare team before trying it.

Highly Active Antiretroviral Therapy (HAART), also called combination antiretroviral therapy (cART), is a treatment for HIV that uses three or more medicines together. It helps stop HIV from making copies of itself, protecting the immune system and slowing the progression to AIDS. HAART also lowers the chance of passing HIV to others, including from mother to baby during childbirth.

Hilar refers to the area where nerves and blood vessels connect to an organ. In bile duct cancer, 'hilar' describes tumors located near where the bile ducts exit the liver. This term helps doctors describe the cancer’s location but is not a diagnosis or treatment by itself. Patients should ask their care team how 'hilar' applies to their specific case for clear understanding and care planning.

HIPAA, or the Health Insurance Portability and Accountability Act, is a U.S. law that protects your health information privacy and helps you keep health insurance when changing or losing jobs. It gives you the right to see your medical records and control who can access them, including family or caregivers. HIPAA also sets rules for keeping electronic health records safe.

HIPEC (Hyperthermic Intraperitoneal Chemotherapy), also called CHPP, is a cancer treatment given during surgery for certain abdominal cancers. It involves circulating a warm liquid with chemotherapy drugs inside the belly after removing visible tumors. The heat helps the drugs work better to kill any remaining cancer cells on the lining of the abdomen.

The Hippocrates Diet is a nutrition approach linked to cancer care discussions, focusing on nutrition, metabolism, inflammation, digestion, immune support, and treatment tolerance. It is sometimes promoted as an alternative or supportive method but lacks strong scientific proof as a cancer treatment. Patients should discuss its use with their healthcare team to understand its role and safety in their individual care.

Hirschsprung disease, also called aganglionic megacolon, is a condition present from birth where nerve cells are missing in part of the large intestine. This causes severe constipation or blockage, making it hard to pass stool. Symptoms may appear soon after birth or later in childhood. While not cancer, it has been linked to a higher risk of certain cancers like thyroid cancer and neuroblastoma.

Histamine is a natural substance in the body that plays a role in allergic reactions and immune responses. In cancer care, medicines called antihistamines may be used to help manage side effects or allergic reactions caused by treatments or blood transfusions. If you hear the term histamine during your care, it’s important to ask your healthcare team how it relates to your specific situation.

Histamine dihydrochloride, also called Maxamine, is a substance studied to help the immune system fight certain cancers. Often used with interleukin-2, it may support immune cells in finding and killing cancer cells. It is not a standard treatment but part of ongoing research, especially for acute myeloid leukemia (AML). Patients should ask their care team how it relates to their care.

Chinese Weevils (Ulomoides dermestoides) are small darkling beetles used in some traditional folk medicine practices, especially in parts of Asia and Latin America. In a practice called coleotherapy, live beetles are swallowed with the belief they may help treat conditions like cancer or asthma. However, there is no strong scientific evidence that this is safe or effective, and swallowing live beetles may carry health risks.

Histiocytic neoplasms, also called histiocytosis, are rare disorders where certain immune cells called histiocytes build up in tissues and organs. These growths can be benign or cancerous and include types like Langerhans cell histiocytosis (LCH) and hemophagocytic lymphohistiocytosis (HLH). They occur most often in children but can affect any age. Understanding the specific type and context is important for treatment and care.

Histiocytoid hemangioma is a rare, non-cancerous growth made of small blood vessels and certain white blood cells. It usually appears as firm pink or red bumps on the skin, often on the head or neck, but can also occur in bones. Though benign, it may cause discomfort and sometimes returns after treatment. It is also known as angiolymphoid hyperplasia with eosinophilia or epithelioid hemangioma.

Histiocytosis is a group of rare disorders where certain white blood cells called histiocytes build up in tissues and organs, potentially causing damage. Types include Langerhans cell histiocytosis (LCH), hemophagocytic lymphohistiocytosis (HLH), and malignant histiocytic disorders. It can affect children and adults. Understanding the specific type and context is important, so patients should discuss what the term means for their care with their healthcare team.

Histologic examination is the process of looking at tissue samples under a microscope to help doctors understand what is happening in the body. It is often used to confirm diagnoses, such as identifying certain tumors like inverted papillomas. For patients and caregivers, it’s important to ask the care team how this examination relates to their specific situation rather than assuming it means a particular diagnosis or treatment.

Histologic grade, also called tumor grade, describes how much cancer cells look like normal cells when viewed under a microscope. It helps doctors understand how quickly the cancer might grow and spread. Grades usually range from low (cells look more normal) to high (cells look very abnormal). This information is used with other factors to guide treatment decisions and estimate prognosis.

Histology is the study of tissues and cells under a microscope. It helps doctors understand the structure and condition of tissues, which is important for diagnosing diseases like cancer. By examining tissue samples, doctors can identify changes that may indicate illness and guide treatment decisions. This entry helps connect the word with diagnoses, testing, treatments, supportive care, research notes, protocols, media, books, people, organizations, and safety concerns.

Histones are proteins found in chromosomes that help organize DNA and control gene activity. In cancer care, drugs called histone deacetylase inhibitors are being studied because they can stop cancer cells from growing. It’s important for patients and caregivers to understand the term in context and ask their care team how it relates to their specific situation, rather than seeing it as a diagnosis or treatment by itself.

Histone deacetylase (HDAC) is an enzyme that changes how DNA is packaged in cells by removing small chemical groups called acetyl groups from proteins called histones. This process can affect gene activity. Drugs called HDAC inhibitors, like romidepsin, are being studied and used in cancer treatment to help stop cancer cells from growing and dividing.

Histone deacetylase inhibitors (HDAC inhibitors) are medicines that can stop cancer cells from dividing and may help kill them. They work by changing chemical signals inside cells that control gene activity. These drugs are being studied and used to treat some cancers, including certain blood cancers. If you see this term, it’s important to ask your care team how it relates to your treatment.

Histone methyltransferase inhibitors (HMT inhibitors) are medicines being studied to treat some types of cancer. They work by blocking enzymes that affect gene activity and cell growth. These drugs are a form of targeted therapy and may help stop cancer cells from growing. Patients should ask their care team how this term applies to their specific situation, as it is not a diagnosis or a treatment plan by itself.

Histopathology is the microscopic study of tissue samples to understand disease. In cancer care, it involves examining biopsies or surgical specimens to help diagnose cancer and guide treatment. The tissue is carefully prepared and stained so a pathologist can look for abnormal cells. Patients should ask their care team how histopathology results apply to their specific situation rather than interpreting the term alone.

A historic cohort study, also called a retrospective cohort study, is a type of medical research that looks back at existing records to compare groups of people who are similar except for one key factor. Researchers study these groups to see how that factor might affect the chance of developing a disease or health outcome, such as lung cancer in smokers versus non-smokers.

A Historical Control Subject is a person treated in the past whose medical information is used to compare with patients in a current study when no control group is included. This helps researchers understand how a new cancer treatment might work. For patients and caregivers, it’s important to ask your care team what this means for your specific situation rather than assuming it guides your treatment.

The Edison Histotripsy System is a non-invasive ultrasound technology used to mechanically destroy liver tumors without surgery, heat, or radiation. It targets tumors in the liver by creating tiny bubbles that break down tumor tissue. This treatment is mainly for certain liver cancers and is still being studied for other tumors.

Histotripsy is a non-invasive treatment that uses focused ultrasound waves to mechanically break down targeted tissue, mainly liver tumors, without heat, needles, or radiation. It creates tiny bubbles that disrupt tumor cells precisely, guided by imaging. This local treatment is FDA-approved for certain liver cancers but is still being studied for other tumors.

Histrelin acetate is a hormone therapy drug that first raises, then lowers certain hormone levels in the body. It is used to treat conditions like early puberty in children and hormone-sensitive prostate cancer in men. Patients and caregivers should always ask their care team how histrelin acetate applies to their specific situation rather than assuming it means a particular diagnosis or treatment.

HIV, or human immunodeficiency virus, is a virus that harms the immune system by destroying important white blood cells. This makes it harder for the body to fight infections and some cancers. People living with HIV have a higher risk of certain cancers. Treatments can help manage HIV and improve health, but there is no cure. Understanding HIV’s role in cancer risk is important for patients and caregivers.

An HIV antibody test is the most common way to check for HIV infection. It looks for antibodies—proteins your immune system makes when it meets HIV—in blood, urine, or saliva. It can take from 2 weeks up to 6 months after infection for antibodies to show. If you see this term, ask your care team what it means for you personally, rather than assuming it is a diagnosis or treatment plan.

An HIV antibody test is the most common way to check for HIV infection. It looks for antibodies—proteins your immune system makes when it meets HIV—in blood, urine, or saliva. It can take from 2 weeks up to 6 months after infection for antibodies to show. If you see this term, ask your care team what it means for you personally, rather than assuming it is a diagnosis or treatment plan.

An HIV DNA test is a blood test that looks for the genetic material of HIV, the virus that causes AIDS. It can detect HIV infection about 9 to 11 days after exposure. This test is often used for early detection in adults and to check for HIV in babies born to mothers with HIV. Patients should discuss what the test results mean with their healthcare team.

HIV Negative means a person does not have the human immunodeficiency virus (HIV), the virus that can lead to AIDS. For patients and caregivers, it’s important to understand this term in context and ask the healthcare team how it relates to their specific situation, rather than seeing it as a diagnosis or treatment decision on its own.

HIV positive means a person is infected with the human immunodeficiency virus (HIV), the virus that causes AIDS. People who are HIV positive may have a higher risk for certain infections and cancers, including those linked to human papillomavirus (HPV). For example, anal cancer screening with an anal Pap test may be recommended for some people living with HIV to find precancerous changes early.

An HIV RNA test looks for the genetic material of the HIV virus in the blood. It can detect HIV infection very early, about 9 to 11 days after exposure. This test helps find HIV soon after infection, but it’s important to discuss what the results mean with your healthcare team rather than interpreting the test alone.

An HIV test checks for infection with the human immunodeficiency virus (HIV), the virus that can lead to AIDS. It usually looks for antibodies to HIV or the virus’s genetic material in blood, urine, or mouth fluid. Different types of tests can detect HIV at different times after exposure. Testing helps find HIV early so treatment can start and reduce the chance of spreading the virus to others.

The HIV window period is the time after a person becomes infected with HIV but before standard tests can reliably detect the infection. For antibody tests, this period can last from 2 weeks up to 6 months. During this time, a person may test negative yet still be able to spread HIV. Understanding this period helps patients and caregivers interpret test results and discuss timing with their care team.

Hives, also called urticaria, are red or skin-colored raised bumps on the skin that often itch. They can appear suddenly and may be caused by allergic reactions, infections, stress, or other triggers. While usually harmless and temporary, some types of hives may signal more serious conditions. If you see the word “hives” in your medical information, ask your care team what it means for you personally.

HLA, or human leukocyte antigen, is a molecule found on most cells that helps the immune system recognize what belongs in the body. Testing for HLA is important before organ or stem cell transplants to find a good tissue match. In cancer care, certain HLA types help doctors decide if specific treatments, like some immunotherapies, may work for a patient. Always ask your care team how HLA relates to your care.

HLA Matching, also called human leukocyte antigen matching, is a test done before stem cell or organ transplants to see if the donor’s tissue matches the recipient’s. HLAs are molecules on most cells that help the immune system recognize what belongs in the body. Matching helps reduce the risk of transplant rejection and complications. If you see this term, ask your care team how it relates to your specific situation.

The HLA-A*02:01 antigen is a protein found on the surface of many cells in the body, including some cancer cells like melanoma. It helps the immune system recognize and respond to these cells. Some cancer treatments, such as certain drugs for eye melanoma, work only in patients who have this antigen. It’s important to discuss with your care team what this means for your specific situation.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and serious disorder where certain white blood cells become overactive and attack the body’s own tissues. It can be inherited or triggered by infections, immune problems, or cancer. HLH causes inflammation and damage in organs like the liver, spleen, and skin. Treatments like emapalumab (Gamifant) may help calm the immune system when standard therapies don’t work.

Hll1, also known as IMMU-110 or milatuzumab, is a type of monoclonal antibody being studied to help treat certain cancers like multiple myeloma. It works by targeting a protein called CD74 found on some cancer cells. If you see this term in your medical information, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

HLRCC (Hereditary Leiomyomatosis and Renal Cell Cancer) is a rare inherited condition caused by changes in the FH gene. It leads to non-cancerous skin and uterine tumors and increases the risk of a specific type of kidney cancer. Symptoms usually appear in young adulthood. Knowing about HLRCC can help with early detection and monitoring of kidney cancer risk.

HMG-CoA reductase inhibitors, also known as statins, are medicines that lower cholesterol by blocking an enzyme your body uses to make it. They are often used to reduce the risk of heart problems. In cancer care, you might see this term when doctors discuss managing overall health or side effects, but it is not a cancer treatment by itself. Always ask your care team how it relates to your personal care.

HMGA1 is a protein found at high levels in many cancer cells. It helps organize DNA inside cells and plays a role in how cells grow and survive. For patients and caregivers, it’s important to understand HMGA1 as part of a larger picture and to ask the care team how it relates to their specific situation, rather than seeing it as a diagnosis or treatment on its own.

HMR 1275, also known as alvocidib or flavopiridol, is a drug being studied to treat certain cancers. It works by blocking proteins that cancer cells need to grow and divide. While it is not yet a standard treatment, it may be offered in clinical trials. Patients should talk with their care team to understand if and how this drug might relate to their care.

HMT inhibitors, or histone methyltransferase inhibitors, are medicines being studied to treat some types of cancer. They work by blocking enzymes that affect gene activity and cell growth. These drugs are a form of targeted therapy and may help stop cancer cells from growing. If you see this term, ask your care team how it applies to your specific situation.

Hereditary Nonpolyposis Colorectal Cancer (HNPCC), also called Lynch syndrome, is an inherited condition that raises the risk of colon cancer and several other cancers. It is caused by changes in genes that normally help fix DNA mistakes. Testing tumor tissue or blood can help identify if someone has this condition, which can guide care and inform family members about their risks.

Hodgkin and Reed-Sternberg cells are a type of abnormal cell found in people with Hodgkin lymphoma, a cancer of the lymph system. These cells are important because their presence helps doctors diagnose this disease. The number of these cells can increase as the disease progresses. If you see this term, it’s best to ask your care team what it means for your specific situation rather than assuming it alone defines your diagnosis or treatment.

Hodgkin disease, also called Hodgkin lymphoma, is a cancer that starts in the lymph system, part of the immune system. It often causes painless swelling of lymph nodes, fever, night sweats, and weight loss. Hodgkin lymphoma can often be cured, especially when found early. Understanding the term and asking your care team how it applies to you is important for managing your care.

Hodgkin lymphoma, also called Hodgkin disease, is a cancer that starts in the lymph system, part of the immune system. It often causes painless swollen lymph nodes, fever, night sweats, and weight loss. Hodgkin lymphoma can often be cured, especially when found early. It is important to understand the term in context and discuss what it means for each person with the care team.

A Holistic Cancer Diet is a nutrition approach discussed in cancer care to support overall health, digestion, immune strength, and treatment tolerance. It may be used alongside conventional treatments or as part of alternative care. Patients should review any diet changes with their healthcare team to ensure safety and fit with their specific cancer situation.

The Addiction Spectrum / Holistic Recovery is a broad approach sometimes discussed in cancer care to support symptom relief, nutrition, treatment tolerance, recovery after surgery or chemotherapy, immune or metabolic health, and overall quality of life. People may explore it as a complementary method to regain control and resilience during cancer treatment. Always talk with your healthcare team before trying it.

Holotropic and Transformational Breathwork is a spiritual and emotional practice sometimes used by people with cancer to help reduce fear, process emotions, and find personal meaning. It is not a medical treatment for cancer itself. Patients should discuss its use with their care team to understand how it fits with their overall care and safety needs.

Holy thistle, also called blessed thistle, cardin, spotted thistle, or St. Benedict’s thistle, is a plant whose leaves, stems, and flowers have been used in some cultures to help with certain health issues. It may have anti-inflammatory and anticancer effects, but these are not proven or part of standard cancer treatment. Always talk with your healthcare team before using herbal products like holy thistle.

Homeopathic medicine, also called homeopathy, is an alternative approach that uses very small amounts of natural substances prepared in a special way. It is based on the idea that substances causing symptoms in healthy people can help treat similar symptoms in sick people. Some patients and communities connect homeopathy with cancer prevention, treatment support, or symptom relief, but it is not a proven or standard cancer therapy.

Homeopathy, also called homeopathic medicine, is an alternative approach that uses highly diluted natural substances to restore health. Some people connect it with cancer prevention, treatment support, or symptom relief. However, homeopathy is not a scientifically proven cancer treatment and is not part of standard medical care. Patients should discuss any use of homeopathy with their healthcare team to ensure safe and coordinated care.

Homeostasis is the body’s way of keeping its internal environment stable and balanced. It constantly adjusts things like temperature, blood pressure, blood sugar, and oxygen levels to help the body work properly. This balance is important for overall health and how the body responds to illness or treatment. This entry helps connect the word with diagnoses, testing, treatments, supportive care, research notes, protocols, media, books, people, organizations, and safety concerns.

Homeostatic refers to the body’s natural balance where important factors like temperature, fluid levels, and chemicals are kept within healthy limits. This balance helps the body work properly. For patients and caregivers, it’s important to understand how homeostatic relates to an individual’s health by asking the care team, rather than seeing it as a diagnosis or treatment on its own.

Homoharringtonine, also known as omacetaxine mepesuccinate or Synribo, is a drug used to treat adults with certain types of chronic myeloid leukemia (CML) when other treatments called tyrosine kinase inhibitors are not effective or cannot be used. It works by blocking proteins involved in cancer cell growth. It may also be studied for other cancers. If you see this term, ask your care team how it relates to your treatment.

The Homologous Recombination Repair (HRR) Pathway is a natural process in cells where proteins work together to fix damaged DNA. When this pathway doesn’t work properly, it can lead to diseases like cancer. You might see this term in medical reports or discussions about cancer treatment. It’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

A homozygous genotype means a person has two identical copies of the same gene—one from each parent. Both copies can be normal or both can have the same mutation (change). This term describes a genetic detail and is not a diagnosis or treatment by itself. If you see this term, ask your care team how it relates to your health and care plan.

Hookah, also called a water pipe, is a device used to smoke flavored tobacco heated by charcoal. The smoke passes through water before being inhaled. Hookah smoke contains nicotine and many harmful chemicals that can cause addiction and health problems similar to cigarette smoking. It is important to understand hookah use in context and discuss its meaning and risks with your care team.

Hormonal contraception is a type of birth control that uses hormones like estrogen and progesterone to prevent pregnancy. It can come as pills, patches, injections, implants, or devices placed in the vagina or uterus. While hormonal contraceptives are effective, some studies show they may slightly increase the risk of breast and cervical cancers, but may lower the risk of other cancers. Always discuss personal risks and benefits with your healthcare team.

Hormonal therapy, also called endocrine therapy or hormone treatment, is a cancer treatment that works by adding, blocking, or removing hormones. Some cancers, like breast and prostate cancer, need hormones to grow. This therapy helps slow or stop cancer growth by changing hormone levels or blocking their effects. It’s important to ask your care team how hormonal therapy applies to your specific situation.

Hormones are natural chemicals made by glands in the body that travel through the bloodstream to control how cells and organs work. In cancer care, hormone therapy may be used to block hormones that help certain cancers grow. Hormones also affect many body functions, and changes in hormone levels can cause symptoms or health issues.

Hormone receptors are proteins found on or inside cells that attach to specific hormones. Knowing if cancer cells have hormone receptors helps doctors plan treatment, especially for breast cancer. Hormone receptor status is not a diagnosis by itself but a piece of information that guides therapy decisions. Patients should discuss what hormone receptor results mean for their individual care with their medical team.

Hormone receptor negative means cancer cells do not have proteins called hormone receptors that attach to hormones like estrogen or progesterone. These cancers do not rely on these hormones to grow. Knowing this helps doctors decide if hormone therapies, which lower hormone levels or block their effects, are likely to work. It’s important to discuss what this means for your specific care with your medical team.

Hormone receptor positive describes cancer cells that have proteins (receptors) for hormones like estrogen or progesterone. These cancers may grow in response to these hormones. Knowing if a breast cancer is hormone receptor positive helps doctors decide if hormone therapy, such as aromatase inhibitors, might be helpful as part of treatment. It’s important to discuss what this means for each person with the care team.

Hormone receptor status describes whether cancer cells have special proteins called hormone receptors that attach to hormones like estrogen or progesterone. Knowing this helps doctors plan treatment, especially for breast cancer. It’s important to understand hormone receptor status as part of the bigger picture of your cancer and to ask your care team what it means for your specific case.

A hormone receptor test checks cancer tissue for proteins called hormone receptors. These receptors allow hormones like estrogen or progesterone to attach to cancer cells, which can help the cancer grow. Knowing if cancer cells have these receptors helps doctors decide if hormone-blocking treatments might be helpful. This test is especially important in breast cancer care but should be understood as part of a larger treatment plan.

Hormone Replacement Therapy (HRT) is treatment that replaces hormones the body no longer makes enough of, often used for women during and after menopause to relieve symptoms like hot flashes and vaginal dryness. It may also help protect bones. HRT comes in different forms, including pills, patches, creams, and gels. It has benefits but also some risks, so it’s important to discuss with your healthcare provider whether it’s right for you.

Hormone responsive cancer is a type of cancer that can be affected by hormone treatments. This means the cancer’s growth may slow down or stop when hormones are blocked or altered. Understanding if a cancer is hormone responsive helps guide treatment choices and can influence how doctors manage the disease.

Hormone therapy, also called endocrine therapy or hormonal therapy, is a treatment that adds, blocks, or removes hormones to slow or stop cancer growth. It is often used for cancers like breast and prostate cancer that need hormones to grow. Hormone therapy can be part of a treatment plan or used to manage symptoms, but its meaning and role vary depending on the individual case.

Hormone treatment, also called endocrine therapy or hormonal therapy, uses medicines or surgery to add, block, or remove hormones. It helps slow or stop the growth of certain cancers, like breast and prostate cancer, that need hormones to grow. Understanding hormone treatment can help you know why it’s part of your care and what to expect during your treatment.

Hormone-refractory, also called hormone-resistant, describes cancer that no longer responds well to hormone therapy. This often happens in prostate cancer when the tumor keeps growing even after treatments lower male hormone levels. If you see this term, it’s important to ask your care team what it means for your treatment and monitoring plan.

Hormone-resistant (also called hormone-refractory) describes cancer that no longer responds well to hormone therapy. This often happens in prostate cancer when tumors keep growing despite treatments that lower male hormone levels. If you see this term, it’s important to ask your care team what it means for your treatment and monitoring plan, as it describes how the cancer behaves rather than a specific diagnosis.

Hormone-sensitive prostate cancer is a type of prostate cancer that needs male hormones called androgens, like testosterone, to grow. Many early prostate cancers rely on these hormones, so treatments that lower androgen levels or block their effects can help control the cancer. You might hear this cancer called androgen-dependent, androgen-sensitive, castrate-sensitive, or hormone-sensitive prostate cancer.

Horner syndrome is a group of symptoms caused by damage to nerves that control the eye and face on one side. It can cause a drooping eyelid, a smaller pupil, and less sweating on the affected side. It is not a disease itself but a sign that something may be affecting the nerves, such as injury, tumor, or medical procedures. If you hear this term, ask your care team what it means for you or your loved one.

Hospice is a special type of care for people near the end of life who have stopped treatments aimed at curing their illness. It focuses on relieving pain and other symptoms, and providing emotional, social, and spiritual support to patients and their families. Hospice care can take place at home, in a hospice center, hospital, or nursing facility, and aims to help patients be as comfortable and alert as possible.

Hospice and palliative care are approaches that focus on relieving symptoms and improving comfort for people with serious illnesses like cancer. Palliative care can be given alongside treatments at any stage, while hospice care is for those near the end of life who have stopped treatments aimed at curing the illness. Both provide support for patients and families to improve quality of life.

A hospice center is a special place that provides care for people near the end of life who have stopped treatments aimed at curing their illness. It offers physical, emotional, social, and spiritual support to patients and their families. Hospice centers may also provide short-term respite care to give family caregivers a break. Hospice care focuses on comfort and symptom relief rather than curing the disease.

A hospitalist is a doctor who manages and coordinates your medical care while you are in the hospital. They work closely with your personal doctor and other healthcare team members to make sure you get the right care during your hospital stay. If you see this term, it’s important to ask your care team how it applies to your situation.

A host cell is a cell that has been infected by a virus or another microorganism. In cancer research, some viruses, like Newcastle disease virus, can infect host cells and may replicate faster in cancer cells than in normal cells. Understanding what a host cell is can help patients and caregivers ask informed questions about treatments or test results involving viruses and cancer cells.

A hot flash is a sudden feeling of warmth, often with sweating and flushing, that can happen during cancer treatment or after surgery like removal of testicles in prostate cancer. Hot flashes are common in both women and men and may be linked to changes in hormone levels caused by cancer or its treatments. Managing hot flashes often involves lifestyle changes, medications, or complementary therapies like acupuncture.

A hot nodule is a thyroid nodule that absorbs more radioactive material than the surrounding thyroid tissue during a scan. Most hot nodules produce thyroid hormone and are usually benign (not cancer). They may cause symptoms if large or pressing on nearby structures. Sometimes surgery or other treatments are needed if the nodule grows, causes symptoms, or cannot be clearly ruled out as cancer.

A hot tumor is a type of cancer that tends to trigger a strong immune response. These tumors often have many molecules on their surface that help immune cells, called T cells, recognize and attack them. Cancers like melanoma, non-small cell lung cancer, and bladder, head and neck, kidney, and liver cancers are often considered hot tumors. Understanding this term can help patients talk with their care team about treatment options like immunotherapy.

A hotspot is a specific area in a gene or DNA that is more likely to have mutations, or changes. In cancer care, identifying hotspots can help doctors understand how a tumor behaves or which treatments might work best. If you see the word “hotspot” in your medical records, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

The Hoxsey Dietary Program is a diet and nutrition plan linked to the broader Hoxsey system, an alternative cancer approach. It is discussed for its potential effects on nutrition, metabolism, inflammation, digestion, immune support, and treatment tolerance. However, it is not an approved cancer treatment and should be reviewed carefully with healthcare providers before use.

Hoxsey Herbal Therapy is an alternative cancer treatment involving herbal mixtures, dietary changes, and other remedies. It has been promoted as a cancer cure but lacks scientific evidence of effectiveness. Major medical organizations do not recommend it, and its use may delay proven cancer treatments. This entry helps connect the word with diagnoses, testing, treatments, supportive care, research notes, protocols, media, books, people, organizations, and safety concerns.

HPPH is a drug used in a cancer treatment called photodynamic therapy. It is absorbed by tumor cells and becomes active when exposed to a special light, helping to kill cancer cells. Patients may hear about HPPH in treatment discussions or clinical trials, but it is important to ask your care team how it relates to your specific situation.

Hereditary Papillary Renal Cancer (HPRC) is a rare inherited condition that increases the risk of developing type 1 papillary kidney cancer. This cancer starts in the small tubes inside the kidneys that filter blood and make urine. HPRC often affects both kidneys and may cause multiple tumors. It is linked to changes in the MET gene and is part of hereditary cancer syndromes.

HPV, or human papillomavirus, is a group of more than 200 common viruses. Some types can cause warts, while others can lead to cancers such as cervical, anal, throat, and penile cancer. HPV spreads mainly through intimate skin-to-skin contact, often during sexual activity. Vaccines can protect against many cancer-causing types of HPV, and regular screening helps find early changes before cancer develops.

HPV 16 (Human Papillomavirus 16) is a common sexually transmitted virus that can cause long-lasting infections. If not treated, these infections may lead to cell changes that can develop into cancer over time. HPV 16 is linked to several cancers, including cervical, anal, throat, and others. Regular screening and vaccination can help prevent HPV-related cancers.

HPV 18 (Human Papillomavirus 18) is a common sexually transmitted virus that can cause long-lasting infections. If not treated, these infections may lead to cell changes that can develop into cancer, especially cervical cancer. HPV 18 is one of the high-risk types of HPV linked to several cancers affecting the cervix, anus, throat, and genital areas.

The HPV DNA Test is a lab test that checks cells from the cervix for DNA from human papillomavirus (HPV), a virus linked to cervical cancer. It helps find early changes in cervical cells that might lead to cancer. This test is often used in cervical cancer screening and may be called the Human Papillomavirus DNA Test. It can detect infections that might need follow-up but sometimes finds infections that won’t cause cancer.

An HPV RNA test is a lab test that checks cells from the cervix for RNA of common types of human papillomavirus (HPV). HPV infection can cause changes in cervical cells that may lead to cervical cancer. This test helps detect high-risk HPV infections and precancerous changes early, often alongside a Pap test, to support cervical cancer screening and prevention.

An HPV test checks cervical cells for infection with high-risk types of human papillomavirus (HPV) that can cause cervical cancer. It helps find HPV infections and early cell changes before symptoms appear, making cervical cancer easier to prevent or treat. The test is done using a sample collected by a healthcare provider during a pelvic exam.

The HPV vaccine helps protect against infection by certain types of human papillomavirus (HPV), viruses that can cause genital warts and several cancers, including cervical, anal, and throat cancers. It is usually given to children and young adults before exposure to HPV. The vaccine is safe and effective in reducing the risk of HPV-related health problems.

The HPV/Pap cotest is a cervical cancer screening that combines two tests: the HPV test, which looks for high-risk human papillomavirus types that can cause cervical cancer, and the Pap test, which checks cervical cells for changes that might lead to cancer. This combined test is often done every 5 years for people aged 30 to 65 and helps find abnormal cells or cancer earlier than a Pap test alone.

The HRAS gene makes a protein that helps control cell growth and division. Changes (mutations) in this gene can be found in some cancers, including bladder cancer, where they may affect how the cancer grows or comes back after treatment. HRAS mutations are also linked to a rare genetic condition called Costello syndrome. If you see HRAS mentioned in your care, ask your healthcare team what it means for your specific situation.

The HRR Pathway, or Homologous Recombination Repair Pathway, is a natural process in cells where proteins work together to fix damaged DNA. When this repair system doesn’t work properly, it can increase the risk of diseases like cancer. You might see this term in medical reports or discussions about cancer treatment. It’s important to ask your care team what it means for your specific health situation.

Hormone Replacement Therapy (HRT) is treatment that replaces hormones the body no longer makes enough of, often used during and after menopause to relieve symptoms like hot flashes and vaginal dryness. In cancer care, using HRT requires careful consideration because some cancers grow in response to hormones. Patients should discuss risks and benefits with their healthcare team before starting HRT.

HSIL stands for High-Grade Squamous Intraepithelial Lesion. It means there are moderately or severely abnormal cells on the cervix that could develop into cervical cancer if not treated. HSIL is a more serious finding than mild changes and usually requires follow-up testing and treatment to prevent cancer. It may also appear under related names such as High-Grade Squamous Intraepithelial Lesion.

HSP stands for heat-shock protein or stress protein. These proteins help protect cells from stress like heat, cold, or low oxygen. In cancer care, HSPs may be involved in how cancer cells survive and grow. Sometimes drugs that target HSPs are studied to treat cancer. If you see this term, ask your care team what it means for your specific situation.

HSPC, or hormone-sensitive prostate cancer, is a type of prostate cancer that needs male hormones called androgens, like testosterone, to grow. Many early prostate cancers depend on these hormones, so treatments that lower androgen levels or block their effects can often slow or stop the cancer’s growth. You may also hear this called androgen-dependent or castrate-sensitive prostate cancer.

Herpes Simplex Virus (HSV) is a common virus that causes infections like cold sores around the mouth (HSV-1) and sores in the genital area (HSV-2). These infections are widespread and can spread even without visible symptoms. HSV is part of a larger family called human herpesviruses (HHV). Understanding HSV is important, especially for people with weakened immune systems, such as those undergoing cancer treatment.

HTLV-1 (Human T-Cell Leukemia Virus Type 1) is a virus that infects certain white blood cells called T-cells. It can cause rare cancers like adult T-cell leukemia/lymphoma (ATLL). HTLV-1 spreads through blood contact, sexual contact, and from mother to child during birth or breastfeeding. Understanding this virus helps patients and caregivers recognize its role in some cancers and ask informed questions about diagnosis and care.

Hu14.18-Interleukin-2 Fusion Protein is an experimental cancer drug that combines a monoclonal antibody (hu14.18) with a protein called interleukin-2 (IL-2). The antibody targets cancer cells and delivers IL-2 to stimulate the immune system to attack those cells. Patients should discuss with their care team how this treatment might apply to their specific situation.

Hu3S193 is a laboratory-made monoclonal antibody that binds to a protein called Lewis(y), which is found on certain cancer cells, including colon, breast, lung, ovary, and prostate cancers. It is being studied as a possible treatment but is not a diagnosis or standard therapy. Patients should discuss with their care team how this term relates to their individual care.

HuAFP31 is a laboratory-made monoclonal antibody that attaches to a protein called alpha fetoprotein (AFP), found on some cancer cells. It is being studied as a way to help the immune system find and attack certain tumors, especially in liver cancer. HuAFP31 may be linked to a small amount of radioactive material to help kill cancer cells. Patients should discuss with their care team what this term means for their specific situation.

Huang Lian is a traditional Chinese herb used for various health issues. It is being studied for its potential role in cancer treatment. Patients should discuss its use with their healthcare team to understand what it means for their specific care, rather than seeing it as a direct treatment or diagnosis.

Huc242-Dm4 is an experimental cancer treatment made by linking a lab-made antibody called huC242 to a toxic drug named maytansinoid DM4. This combination aims to target cancer cells specifically, delivering the drug directly to them to block their growth while limiting harm to healthy cells. It is still being studied and is not yet widely available or approved for general use.

HuHMFG1 is a laboratory-made monoclonal antibody studied for treating some cancers. It targets a protein called MUC1 found on certain cancer cells, including breast, ovarian, pancreatic, stomach, and colon cancers. Patients should discuss with their care team how this term relates to their specific situation rather than viewing it as a diagnosis or treatment recommendation.

The Hulda Clark Protocol, also called the Clark Zapper, is an alternative health approach that uses a device called the Zapper along with herbal cleanses and toxin avoidance. Some people with cancer explore it for symptom relief like pain, inflammation, or energy support. However, it is not supported by scientific evidence as a cancer treatment and may carry risks, so patients should discuss it with their healthcare team before use.

The Hulda Clark Protocol, also called the Clark Zapper, is an alternative health approach that uses a device claiming to send electrical frequencies through the body to kill parasites and toxins. It includes herbal cleanses and avoiding pollutants. Some people with cancer explore it for symptom relief like pain or inflammation, but it is not supported by scientific evidence as a cancer treatment and may carry risks. Always discuss with your healthcare team before use.

Huluc63 is another name for elotuzumab, a medicine used to treat multiple myeloma, a type of blood cancer. It works by helping the immune system recognize and attack cancer cells. It is given through an intravenous (IV) infusion, often with other cancer drugs like lenalidomide or pomalidomide and dexamethasone. If you see this name in your care, ask your healthcare team how it applies to your treatment.

Human corticotropin-releasing factor (hCRF) is a natural substance made by the brain that may help reduce swelling (edema) in the brain. It is being studied as a possible treatment to ease symptoms caused by brain swelling, especially in brain cancer. Patients may see this term in medical reports or discussions and should ask their care team how it relates to their situation.

Human EGF Receptor 2, also called HER2, HER2/Neu, or c-erbB-2, is a protein found on some cells that helps control normal cell growth. Some cancers, such as breast and ovarian cancer, may have too much HER2, which can make cancer cells grow faster and spread. Testing for HER2 helps doctors understand the cancer and choose treatments that target these cells.

Human Epidermal Growth Factor Receptor 2 (HER2) is a protein found on the surface of some cells that helps control normal cell growth. Some cancer cells, especially in breast, ovarian, bladder, pancreatic, stomach, and esophageal cancers, may have higher than normal amounts of HER2. Testing for HER2 helps doctors plan treatment and understand how the cancer might behave.

HER2 Negative means cancer cells have little or no HER2 protein on their surface. HER2 is a protein that helps control cell growth. Cancers that are HER2 negative often grow more slowly and may be less likely to spread or come back than cancers with high HER2 levels. This term is commonly used in breast cancer and helps guide treatment decisions.

Human Epidermal Growth Factor Receptor 2 Positive (HER2 Positive) means cancer cells have more than the usual amount of a protein called HER2 on their surface. This protein helps control cell growth. When there’s too much HER2, cancer cells may grow faster and spread more easily. Knowing if a cancer is HER2 positive helps doctors choose treatments that specifically target these cells, often improving care for cancers like breast, stomach, and others.

A Human Epidermal Growth Factor Receptor 2 (HER2) test is a lab test that measures the amount of HER2 protein or gene copies on cancer cells. HER2 helps control cell growth. Some cancers, especially breast cancer, may have extra HER2, which can make cancer grow faster. Knowing HER2 status helps doctors plan treatment, including targeted therapies that focus on HER2-positive cancer cells.

Human Epididymis Protein 4 (HE4) is a protein found on cells lining organs like the lungs and ovaries. Higher than normal levels of HE4 may be seen in some cancers, especially ovarian epithelial cancer. Measuring HE4 in the blood can help doctors plan treatment or check if cancer is worsening or has returned. HE4 is one of several tumor markers used in cancer care.

Human herpesviruses are a group of nine viruses that commonly infect people worldwide. They include herpes simplex viruses (causing cold sores and genital herpes), varicella zoster virus (causing chickenpox and shingles), Epstein-Barr virus (linked to mononucleosis and some cancers), cytomegalovirus, and human herpesvirus 8, which is linked to Kaposi sarcoma and certain rare lymph node diseases.

Human Herpesvirus 8 (HHV-8), also called Kaposi sarcoma-associated herpesvirus (KSHV), is a virus linked to several rare cancers and disorders, including Kaposi's sarcoma, a tumor often seen in people with weakened immune systems such as those with AIDS. It can also cause certain lymphomas and Castleman disease. Understanding HHV-8 helps patients and caregivers discuss diagnosis and treatment with their care team.

Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system, making it harder for the body to fight infections and some cancers. HIV can lead to Acquired Immunodeficiency Syndrome (AIDS) if untreated. People living with HIV have a higher risk of certain cancers. Treatments called antiretroviral therapy (ART) help control HIV, allowing many to live long, healthy lives.

Human Leukocyte Antigen (HLA) is a molecule found on most cells that helps the immune system recognize what belongs in the body. HLA testing is important before organ or stem cell transplants to find a good tissue match and reduce the risk of rejection. In cancer care, certain HLA types may also help doctors decide if specific treatments, like some immunotherapies, could work for a patient. Always ask your care team how HLA relates to your care.

Human Leukocyte Antigen Matching, also called HLA Matching, is a test done before stem cell or organ transplants to see if the donor’s tissue matches the recipient’s. HLAs are molecules on most cells that help the immune system recognize what belongs in the body. Matching helps reduce the risk of transplant rejection and complications. If you see this term, ask your care team how it relates to your specific situation.

Human Lymphocyte Antigen (HLA), also called Human Leukocyte Antigen, is a molecule found on most cells that helps the immune system recognize which cells belong in the body. HLA testing is important before organ or stem cell transplants to find a good tissue match and reduce the risk of rejection. In cancer care, certain HLA types may also help doctors decide if specific treatments, like some immunotherapies, could work for a patient.

Human Papillomavirus (HPV) is a group of more than 200 related viruses. Some types can cause warts, while others can lead to cancers such as cervical, anal, throat, and genital cancers. HPV spreads mainly through intimate skin-to-skin contact, including sexual activity. Vaccines are available to help prevent infection with the most harmful types of HPV.

Human Papillomavirus 16 (HPV 16) is a common sexually transmitted virus that can cause long-lasting infections. It is a high-risk type of HPV linked to several cancers, including cervical, anal, throat, penile, vaginal, and vulvar cancers. Regular screening and vaccination can help detect and prevent HPV 16-related cancers. It may also appear under related names such as HPV 16.

Human Papillomavirus 18 (HPV 18) is a common sexually transmitted virus that can cause long-lasting infections. It is one of the high-risk types of HPV linked to several cancers, especially cervical cancer. If not treated, HPV 18 infections may cause cell changes that can develop into cancer over time. Screening tests and vaccines can help detect and prevent HPV 18-related health problems.

The Human Papillomavirus (HPV) DNA Test is a lab test that checks cells from the cervix for DNA from HPV, a common virus linked to cervical cancer. It helps find early changes in cervical cells that might lead to cancer. This test is often used during cervical cancer screening and can detect infections that may need follow-up but sometimes finds infections that won’t cause cancer.

The Human Papillomavirus RNA Test (HPV RNA Test) is a lab test that checks cells from the cervix for RNA of certain types of HPV, a virus that can cause changes in cervical cells. It is often done with a Pap test to help detect HPV infections and early signs of cervical cancer, supporting screening and prevention efforts.

The human papillomavirus (HPV) test checks cervical cells for infection with high-risk types of HPV that can cause cervical cancer. It helps find HPV infections and early cell changes before symptoms appear, making cervical cancer easier to prevent or treat. The test is done using a sample collected by a healthcare provider during a pelvic exam.

The human papillomavirus (HPV) vaccine helps protect against infection by certain types of HPV viruses. These viruses can cause genital warts and several cancers, including cervical, anal, throat, penile, vulvar, and vaginal cancers. The vaccine is usually given to children and young adults before exposure to HPV and is safe and effective in reducing the risk of HPV-related health problems.

Human Participant Protection Regulations, also known as 45 CFR 46 or Protection of Human Subjects, are U.S. federal rules that protect people who take part in research studies. These laws help ensure that research involving human participants is done safely and ethically, requiring clear explanations, informed consent, and ongoing safety monitoring to respect and safeguard participants’ rights and well-being.

Human T-Cell Leukemia Virus Type 1 (HTLV-1) is a virus that infects T-cells, a kind of white blood cell important for the immune system. It can cause rare cancers like adult T-cell leukemia/lymphoma (ATLL). HTLV-1 spreads through blood contact, sexual contact, and from mother to child during birth or breastfeeding. Understanding HTLV-1 helps patients and caregivers recognize its role in some cancers and ask informed questions about diagnosis and care.

Human T-Cell Lymphotropic Virus Type 1 (HTLV-1) is a virus that infects T-cells, a type of white blood cell important for the immune system. It can sometimes cause a rare cancer called adult T-cell leukemia/lymphoma (ATLL). HTLV-1 spreads through blood contact, sexual contact, and from mother to child during birth or breastfeeding. Understanding HTLV-1 helps patients and caregivers ask informed questions about diagnosis and care.

A humanized monoclonal antibody is a lab-made protein designed to target specific proteins in the body. One example, called MEDI-522 or Abegrin, attaches to proteins on blood vessels and may help stop tumors from growing new blood vessels they need to grow. These medicines are still being studied, so it’s important to ask your care team how they might apply to your treatment.

Humanized Monoclonal Antibody MEDI-522, also called Abegrin or etaracizumab, is an experimental medicine studied for some cancers. It is a lab-made protein that attaches to blood vessels in tumors and may stop new blood vessels from forming. This could slow tumor growth and help prevent cancer from spreading. It is not yet a standard treatment and is usually available only through clinical trials.

Humax-Cd20, also known as Arzerra or ofatumumab, is a medicine used to treat certain blood cancers like chronic lymphocytic leukemia (CLL). It works by targeting a protein called CD20 on some white blood cells and cancer cells, helping the immune system attack them. You may see different names for this drug in medical reports or discussions, but they all refer to the same treatment.

A humidifier is a device that adds moisture to the air in a room or home. It can help relieve dryness that causes discomfort such as dry mouth, irritated skin, or breathing issues. Humidifiers are often used at home or in medical settings to improve comfort, but it’s important to use them properly to avoid problems like mold growth or lung irritation.

Humor therapy, also called laughter therapy, uses humor and laughter to help reduce pain and stress and improve well-being. It may include activities like laughter exercises, watching comedy movies, reading funny books, playing games, or visits from clowns. Often used as a complementary approach, it can support people coping with serious illnesses such as cancer. Always ask your care team how humor therapy fits your personal care plan.

Hurthle Cell Neoplasm is a rare type of tumor found in the thyroid gland. It can be either noncancerous (benign) or cancerous (malignant). Understanding this term helps patients and caregivers recognize the nature of certain thyroid growths and the importance of further medical evaluation to determine the best care approach.

Hyaluronidase is an enzyme that breaks down hyaluronic acid, a natural substance in the body that helps keep tissues moist and thick. In cancer care, hyaluronidase is used with certain medicines to help them spread and absorb better when injected under the skin. It is part of some cancer treatments that help the immune system recognize and attack cancer cells, but it is not suitable for all cancers or patients.

Hycamtin (topotecan hydrochloride) is a chemotherapy drug used to treat certain cancers, including ovarian, cervical, and small cell lung cancer. It works by blocking an enzyme that cancer cells need to divide and repair their DNA, which helps kill these rapidly growing cells. Hycamtin may be used alone or with other cancer drugs and is approved by the FDA for specific cancer treatments.

A hydatidiform mole, also called molar pregnancy, is an uncommon growth that starts from pregnancy tissue. It is usually not cancer but can sometimes grow into a rare cancer called invasive hydatidiform mole or chorioadenoma destruens. This condition involves abnormal tissue growth in the uterus after fertilization and requires careful diagnosis and follow-up to guide treatment and prevent complications.

Hydration means keeping your body supplied with enough fluids to stay healthy. In cancer care, hydration is important to help manage symptoms, support nutrition, improve how well treatments work, and aid recovery after surgery or chemotherapy. It may also be part of supportive care to maintain kidney function, balance electrolytes, and improve quality of life during cancer treatment.

Hydrazine sulfate is a chemical compound studied as a treatment for cancer and cancer-related weight loss (cachexia). While it has been explored for its potential to block tumor sugar use and improve appetite, clinical trials have not shown it can shrink tumors or reliably improve survival. It is not approved by the FDA for cancer treatment and may have safety concerns. Patients should discuss its use carefully with their healthcare team.

Hydrea is a brand name for the drug hydroxyurea, used to treat certain types of chronic myelogenous leukemia and head and neck cancer. It works by slowing or stopping cancer cell growth. The same drug, under the brand name Droxia, is used to treat sickle cell anemia. Patients should always ask their care team how Hydrea or Droxia applies to their specific health situation.

Hydrocarbons are chemicals made only of hydrogen and carbon, found in fuels like coal, petroleum, and natural gas. Exposure to some hydrocarbons, especially those formed when materials burn incompletely, may increase the risk of certain cancers. Patients should understand this term in context and discuss with their care team how it relates to their personal health and cancer risk.

Hydrocephalus is a condition where too much cerebrospinal fluid (CSF) builds up in the brain’s ventricles, causing pressure inside the skull. This pressure can lead to symptoms like headaches, blurry vision, balance problems, and memory issues. It can happen at birth or develop later due to injury, infection, tumors, or bleeding. Treatment often involves surgery to drain the excess fluid and relieve pressure.

Hydrocodone bitartrate is a man-made drug based on codeine, a natural substance from the opium poppy plant. It is used to relieve moderate to severe pain and to reduce coughing. In cancer care, it may be part of a pain management plan. Patients and caregivers should discuss with their health care team how this medicine fits into their personal treatment, rather than focusing on the word alone.

Hydrocortisone is a steroid medicine related to the hormone cortisol. It helps reduce inflammation and calm the immune system. In cancer care, it is mainly used to support patients during serious infections or inflammation, not as a cancer treatment. Side effects can include high blood pressure, fluid retention, mood changes, and increased risk of infections. Always ask your care team how hydrocortisone applies to your specific situation.

Hydrogen cyanide is a chemical compound known for its strong toxicity. It can appear as a liquid or gas and is found in some plants, foods, and tobacco smoke. It is used in making products like paper and plastics. In the body, certain immune cells produce hydrogen cyanide to help fight infections. If you see this term in your care, ask your medical team what it means for your situation rather than assuming it relates directly to your diagnosis or.

Hydrogen peroxide is a chemical commonly used as a disinfectant and bleach. In strong concentrations, it can be dangerous and irritate tissues. Some alternative medicine approaches discuss hydrogen peroxide therapy for cancer support, but its use should always be discussed with your care team to understand what it means for you personally.

Hydrogen peroxide therapy is an alternative medicine approach sometimes discussed for cancer support. It involves using hydrogen peroxide, a chemical commonly used as a disinfectant, to affect oxygen levels or the immune system. However, it is not part of standard cancer treatment and lacks strong evidence for safety or effectiveness. Always talk with your care team before considering it.

Hydrolysis is a chemical reaction where water breaks down a compound into smaller parts. In cancer care, this process can be part of how certain drugs work or how the body processes substances. If you see the word hydrolysis in your medical information, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment by itself.

Hydromorphone Hydrochloride is a strong opioid medicine used to treat moderate to severe pain, including pain related to cancer. It is known by brand names such as Dilaudid, Exalgo, and Hydrostat IR. Made from morphine, it works by affecting the brain and nervous system to reduce pain. Because it is powerful, it is used carefully under medical supervision and may cause side effects like dizziness, sleepiness, nausea, and constipation.

Hydronephrosis is a condition where one or both kidneys become enlarged because urine cannot drain properly. It can happen suddenly or slowly and may be caused by kidney stones, tumors, or pressure from nearby organs. Ultrasound is often used to diagnose it, especially during pregnancy. Understanding what hydronephrosis means for you personally is important, so ask your care team for details about your situation.

Hydrostat IR is a strong opioid medicine used to treat moderate to severe pain, including pain related to cancer. It is made from morphine and works by affecting the brain and nervous system to reduce pain. Hydrostat IR is also known by other names such as Dilaudid, Exalgo, and hydromorphone hydrochloride. Because it is powerful, it is used carefully under medical supervision.

Hydroureter is a condition where the ureter, the tube that carries urine from the kidney to the bladder, becomes abnormally enlarged. This swelling happens because something is blocking urine from flowing normally into the bladder. It can be related to various causes, including cancer, and may require medical evaluation to address the blockage and protect kidney health.

Hydroxychloroquine is a medication that reduces immune system activity. It is used to treat some autoimmune diseases and is being studied for certain complications in cancer care. Early in the COVID-19 pandemic, it was discussed as a possible treatment but is no longer widely recommended. Patients may hear about it in cancer care conversations, especially related to supportive care or integrative approaches. Always ask your care team how it applies to your situation.

Hydroxychloroquine for COVID-19 is a medication that was widely discussed early in the pandemic as a possible treatment. In cancer care, it may come up for various reasons, including claims about anticancer effects, symptom relief, or supportive care. However, mainstream guidelines generally do not recommend it for COVID-19 due to lack of clear benefit and safety concerns. Patients should always discuss its use with their cancer care team.

Hydroxydaunorubicin, also known as Adriamycin or doxorubicin hydrochloride, is a chemotherapy drug used to treat many types of cancer. It works by damaging cancer cells’ DNA and slowing their growth. You may hear this name during treatment discussions or see it in medical reports. It is often combined with other drugs in chemotherapy plans.

Hydroxymethylglutaryl-Coenzyme A Reductase Inhibitors, also called HMG-CoA reductase inhibitors or statins, are medicines that lower cholesterol by blocking an enzyme your body uses to make it. They are often used to reduce the risk of heart problems. In cancer care, these drugs may be mentioned when managing overall health but are not cancer treatments themselves.

Hydroxyurea is a medication used to treat certain cancers, including chronic myelogenous leukemia that does not respond to other treatments, and some head and neck cancers. It works by slowing or stopping cancer cell growth. Hydroxyurea is also used under different brand names to treat sickle cell anemia. Patients should ask their care team how this drug applies to their specific health situation.

Hygiene means the practices and conditions that help keep people healthy and prevent the spread of infections. In cancer care, hygiene includes things like handwashing, cleaning surfaces, and safe care at home to protect patients who may have weaker immune systems. It’s important to understand hygiene in context and ask your healthcare team how it applies to your care.

Hyper-CVAD is a chemotherapy treatment used mainly for certain types of leukemia and aggressive lymphomas. It combines several cancer-fighting drugs given in smaller, more frequent doses to help reduce side effects. Before starting, patients undergo careful health checks to ensure they can safely receive this intensive therapy. It may also appear under related names such as Hyper-CVAD Regimen.

Hyper-CVAD is a chemotherapy treatment used mainly for certain aggressive blood cancers like some leukemias and lymphomas. It combines several cancer-fighting drugs given in smaller, more frequent doses to help reduce side effects. Patients usually have a thorough health check before starting to ensure they can safely receive this intensive therapy.

Hyperactivity means having a higher than normal level of activity, which can include restlessness, trouble concentrating, or impulsive behavior. In cancer care, it may come up when discussing symptoms like fatigue or difficulty focusing. Medications like Adderall, a stimulant, might be used to help manage these symptoms, but the term itself is not a diagnosis or treatment recommendation. Always ask your care team how it applies to your situation.

Hyperalgesia is when a person feels more pain than usual from something that normally causes pain. It can happen if nerves are damaged or changed, sometimes due to injury, inflammation, or certain pain medicines like opioids. People with hyperalgesia may feel intense pain even if their injury or illness hasn’t worsened.

Hyperalimentation, also called parenteral nutrition, is a way to provide nutrition directly into the bloodstream through a vein. It is used when a person cannot eat or absorb food normally, such as during cancer treatment. This method helps supply essential nutrients to keep the body strong when eating by mouth is not enough or not possible.

Hyperbaric oxygen therapy (HBOT) is a medical treatment where you breathe pure oxygen in a pressurized chamber. This increases oxygen levels in your body and is used for certain wounds, infections, and carbon monoxide poisoning. In cancer care, it is sometimes studied to help make cancer cells more sensitive to radiation or chemotherapy, but its use as a direct cancer treatment is not proven.

Hyperbilirubinemia means having higher-than-normal levels of bilirubin in the blood. Bilirubin is a yellowish substance made when the body breaks down old red blood cells. This condition is common in newborns because their bodies handle bilirubin differently. It can cause jaundice, which is a yellowing of the skin and eyes. Hyperbilirubinemia can have different causes and may need medical attention to avoid complications.

Hypercalcemia means having higher than normal calcium levels in the blood. Some cancers can cause this condition by affecting bones or how calcium is managed in the body. It can lead to symptoms like weakness, confusion, and nausea. If you see this term in your care, ask your healthcare team what it means for you personally, as it is not a diagnosis by itself but a sign that may need attention.

Hypercortisolism, also called Cushing syndrome, is a condition where the body has too much cortisol, a hormone made by the adrenal glands. It can happen from taking steroid medicines or from certain tumors that cause excess cortisol. Symptoms often include weight gain around the belly and face, muscle weakness, high blood pressure, mood changes, and skin changes like stretch marks.

Hypercytokinemia, also called a cytokine storm, is a strong and uncontrolled immune reaction where the body releases too many cytokines, molecules that help control inflammation. This can cause serious symptoms like high fever, swelling, and fatigue. It may happen due to infections, certain diseases, or as a side effect of some cancer treatments. Early recognition and management are important to prevent complications.

Hyperdiploid describes cancer cells that have more DNA than normal, meaning they contain extra chromosomes. This information can help doctors plan treatment and understand prognosis. For patients and caregivers, it’s important to discuss what hyperdiploid means in the context of the specific cancer and individual case, rather than seeing it as a diagnosis or treatment decision on its own.

Hyperfractionated Radiation Therapy, also called superfractionated radiation therapy, is a type of radiation treatment where the total radiation dose is divided into smaller doses given more than once a day. It is delivered over the same overall time period as standard radiation therapy. Patients should discuss with their care team how this approach fits their specific treatment plan.

Hyperfractionation is a radiation treatment schedule where the total radiation dose is divided into smaller doses given more than once a day. This approach aims to treat cancer effectively while carefully managing side effects. It differs from standard radiation therapy, which usually gives one dose per day over several weeks. Patients should discuss with their care team how hyperfractionation applies to their specific treatment plan.

Hyperglycemia, also called high blood sugar, means having more glucose (a type of sugar) in your blood than normal. It often happens in people with diabetes but can also be caused by other health conditions or medicines. Symptoms may include feeling very thirsty, tired, urinating often, or blurry vision. Managing blood sugar is important for overall health and during cancer care.

Hypericum perforatum, commonly known as St. John’s wort, is a flowering plant traditionally used to help with sleep problems, wound healing, and mild depression. It is also being studied for its potential to reduce some side effects of cancer treatment. However, it can interact with cancer drugs, so it’s important to talk with your healthcare team before using it.

Hyperkeratosis is a condition where the outer layer of the skin becomes thicker than usual due to extra keratin, a protective protein. It can happen from normal skin use like calluses, ongoing skin irritation, or certain genetic conditions. If you see this term in your care, ask your healthcare team what it means for you personally.

Hypernephroma is another name for renal cell carcinoma, the most common type of kidney cancer in adults. It starts in the lining of tiny tubes inside the kidney that filter blood and produce urine. The term may appear in medical reports or discussions, so it’s important for patients and caregivers to ask their care team what it means for their specific situation.

Hyperparathyroidism is a condition where the parathyroid glands make too much parathyroid hormone, causing calcium to leave the bones and increase in the blood. This can lead to symptoms like bone pain and kidney problems. In cancer care, it’s important to understand how this condition affects calcium levels and overall health. Always ask your care team how it applies to your personal situation.

Hyperpigmentation is a common, usually harmless condition where patches of skin become darker than the surrounding areas. It happens when skin cells produce too much melanin, the pigment that gives skin its color. Causes include sun exposure, skin injury, inflammation, hormone changes, certain medicines, and some medical conditions. Treatments vary and should be discussed with your care team to find what’s safe and effective for you.

Hyperplasia means an increase in the number of normal cells in an organ or tissue. It is not cancer, but in some cases, hyperplasia can increase the risk of developing cancer. Common examples include benign prostatic hyperplasia (BPH), which is a noncancerous prostate enlargement, and hyperplasia in breast or uterine tissues. Understanding hyperplasia helps patients discuss their health and risks with their care team.

Hypersensitivity is when the immune system reacts too strongly to a drug or other substance, causing symptoms like itching, rash, or swelling. In cancer care, understanding hypersensitivity helps doctors manage treatments safely and keep patients comfortable. If you see this term, ask your care team how it relates to your situation rather than assuming it means a specific diagnosis or treatment change.

Hypertension, or high blood pressure, is a common condition where the force of blood against artery walls stays too high. It often has no symptoms but can increase the risk of heart problems, stroke, and kidney damage. Managing blood pressure is especially important during cancer care, as some treatments can affect the heart and blood vessels.

Hyperthermia (Cancer Thermal Therapy) is a cancer treatment that uses controlled heat to damage or kill cancer cells. It is often used alongside radiation or chemotherapy to help shrink tumors and improve treatment effectiveness. This therapy can target small areas, larger regions, or the whole body, depending on the cancer type and location. It is not widely available but may be offered at specialized centers.

Hyperthermia, also called cancer thermal therapy, is a treatment that uses controlled heat to damage or kill cancer cells. It is often combined with chemotherapy or radiation to help shrink tumors and improve treatment effects. Heat can be applied to small areas, larger regions, or the whole body using special technologies. Hyperthermia is not widely available and is usually offered at specialized centers.

Hyperthermia therapy is a cancer treatment that uses heat to damage or kill cancer cells and make them more sensitive to radiation or chemotherapy. It is usually given alongside other treatments and can involve heating a small area, a larger region, or the whole body. This therapy is not widely available and is best understood by discussing with your care team how it might fit your specific treatment plan.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC), also called Continuous Hyperthermic Peritoneal Perfusion (CHPP), is a treatment given during surgery for certain cancers that have spread to the lining of the abdomen (peritoneum). It involves circulating a warm liquid containing chemotherapy drugs inside the belly to help kill cancer cells left after tumor removal. The heat helps the chemotherapy work better.

Hyperthermic perfusion is a medical procedure where a warmed solution containing anticancer drugs is used to bathe or flow through the blood vessels of the tissue or organ with a tumor. It is a treatment approach sometimes discussed in cancer care. Patients and caregivers should ask their healthcare team how this procedure might apply to their specific situation rather than assuming it is a diagnosis or standard treatment.

Hyperthyroidism, also called overactive thyroid, is a condition where the thyroid gland makes more thyroid hormones than the body needs. These hormones control energy use and metabolism. Symptoms can include weight loss, rapid heartbeat, sweating, nervousness, and an enlarged thyroid. It can cause problems with the heart, bones, fertility, and pregnancy if untreated. Diagnosis involves blood tests and imaging. Treatments include medicines, radioactive iodine, and surgery.

Hyperuricemia means having too much uric acid in the blood. It can happen as a side effect of some cancer treatments. Most people with hyperuricemia don’t notice symptoms unless it leads to conditions like gout or kidney problems. If you see this term in your care, ask your health team what it means for you personally.

Hypervascular means having a larger number or concentration of blood vessels than usual. This term often appears in medical imaging or pathology reports to describe tissues or tumors with increased blood supply. For patients, it is important to understand that hypervascularity is a descriptive term, not a diagnosis or treatment plan, and should be discussed with the care team to understand its significance in each individual case.

Hypnosis, also called hypnotherapy, is a trance-like state of focused attention and relaxation guided by a trained therapist. In cancer care, it may be used as a complementary approach to help manage symptoms like stress, pain, or nausea, support recovery, and improve quality of life. Always discuss hypnosis with your healthcare team to ensure it is safe alongside your cancer treatments.

Hypnosis, also called hypnotherapy, is a guided state of focused relaxation used alongside cancer care to help manage symptoms like stress, pain, or nausea. It may support recovery after surgery or chemotherapy and improve quality of life. Always talk with your healthcare team before trying hypnosis to ensure it fits safely with your cancer treatments.

Hypnosis, also called hypnotherapy, is a guided state of focused relaxation used alongside cancer care to help manage symptoms like stress, pain, or nausea. It may support recovery after surgery or chemotherapy and improve quality of life. Always talk with your healthcare team before trying hypnosis to ensure it fits safely with your cancer treatments.

Hypofractionated radiation therapy is a way of giving radiation treatment over a shorter time than standard therapy. It involves larger doses per session but fewer sessions overall, meaning treatment is completed in fewer days or weeks. This approach may change how often you visit the clinic and how side effects develop. It’s important to talk with your care team about what this means for your specific treatment plan.

Hypofractionation is a radiation treatment schedule where larger doses of radiation are given in fewer sessions. This approach can shorten the overall treatment time while aiming to effectively treat cancer and manage side effects. Patients should discuss with their care team how hypofractionation fits their specific treatment plan, as it is one way doctors adjust radiation timing to balance benefits and risks.

Hypogammaglobulinemia is a condition where the blood has low levels of antibodies, which are proteins that help fight infections. This means the immune system is weaker, making infections more likely. It can happen due to genetic immune problems or as a side effect of other illnesses or treatments. Patients with this condition need careful monitoring and may need special precautions, especially when traveling or receiving vaccines.

Hypoglycemia means having abnormally low blood sugar, which can cause symptoms like shakiness, sweating, dizziness, and confusion. It often happens in people with diabetes but can also be caused by rare tumors in the pancreas called beta cell tumors. These tumors usually are not cancer but can cause too much insulin, leading to low blood sugar. Treatment depends on the cause and may include eating carbohydrates or surgery.

Hypohidrosis, also called anhidrosis, is a rare condition where the body produces little or no sweat. It can affect the whole body or just a small area. In cancer care, it may happen after treatments like radiation or from skin damage. Because sweating helps cool the body, hypohidrosis can cause overheating and discomfort, so doctors may check for it to keep patients safe and comfortable.

Hypomagnesemia means having lower-than-normal magnesium levels in the blood. Magnesium is an important mineral that helps your muscles, nerves, and heart work properly. Low magnesium can happen for many reasons, including certain medicines, health conditions, or poor nutrition. If you see this term in your health records, ask your care team what it means for you personally.

Hyponatremia means having a lower-than-normal level of sodium in the blood. It can cause symptoms like nausea, headache, confusion, or muscle cramps. In hospital patients, it is linked to a higher risk of serious problems. If you hear this term, it’s important to ask your care team what it means for you personally, rather than treating it as a diagnosis by itself.

Hypopharyngeal cancer is a type of cancer that starts in the tissues of the hypopharynx, the lower part of the throat. Early signs may include a sore throat and ear pain, but symptoms often appear late. Diagnosis involves exams and imaging tests to check the throat and neck. Treatment options depend on the cancer’s stage and the patient’s health. Tobacco use and heavy drinking increase the risk.

The hypopharynx is the bottom part of your throat, located behind the voice box and above the esophagus and windpipe. It helps direct food and air. Cancer that starts here is called hypopharyngeal cancer. Tobacco use and heavy drinking increase the risk. Symptoms may include a sore throat or ear pain. Diagnosis involves exams and imaging to check for cancer and its spread.

Hypophosphatemia means having a lower-than-normal level of phosphate in the blood. Phosphate is a mineral important for energy and bone health. It is rarely low due to diet alone because phosphate is common in many foods. More often, hypophosphatemia happens because of illness or medical treatments. If you see this term, ask your care team what it means for your specific health situation.

Hypopigmentation is a condition where patches of skin become lighter than usual because the skin cells produce less pigment called melanin. It can affect small or large areas and may result from skin injury, inflammation, infection, medical conditions, or certain treatments like laser therapy. Understanding hypopigmentation helps with skin care and sun protection, especially in cancer prevention and treatment.

Hypospadias is a birth difference where the opening of the urethra (the tube that carries urine out of the body) is not in its usual place. In boys, it often opens on the underside of the penis instead of the tip. This condition is more common in males and can be fixed with surgery. Children with hypospadias may have a higher chance of developing Wilms tumor, a type of kidney cancer. It’s important to discuss what this means for each.

Hypotension means abnormally low blood pressure. It can cause symptoms like dizziness, fainting, or weakness when the blood pressure drops too low to supply enough oxygen and nutrients to the body’s organs. In cancer care, hypotension may occur due to infections, blood loss, or side effects of treatments. If you see this term in your medical information, ask your care team what it means for your specific situation.

The hypothalamus is a small but important part of the brain that helps control body temperature, hunger, thirst, and other vital functions. It links the nervous system to the hormone-producing endocrine system, playing a key role in keeping your body’s balance. In cancer care, changes involving the hypothalamus or related hormones may affect symptoms or treatment plans.

A hypothesis is a proposed explanation or idea that scientists use to explore and understand observations. In cancer care, it helps researchers and doctors form questions and design studies to test new treatments or understand disease behavior. For patients, it’s important to ask your care team how a hypothesis relates to your specific situation rather than assuming it is a diagnosis or treatment plan.

Hypothyroidism, also called underactive thyroid, happens when the thyroid gland does not make enough thyroid hormones. These hormones help control your body’s energy use and affect many body functions. Symptoms can include feeling tired, weight gain, dry skin, and sensitivity to cold. It is diagnosed with blood tests and sometimes imaging. Treatment usually involves daily hormone replacement medicine.

Hypotrichosis is a rare condition usually present at birth, where little or no hair grows on the head or other parts of the body. Hair in affected areas is often short, dry, rough, and may break easily. It is linked to certain genetic syndromes. For patients and caregivers, it’s important to understand how this term applies personally by discussing it with the care team rather than viewing it as a diagnosis or treatment on its own.

Hypoxemia means having too little oxygen in the blood. It can happen when the lungs or heart are not working well, or when oxygen levels in the air are low. Symptoms may include shortness of breath, fast breathing, or bluish skin. In cancer care, hypoxemia can affect treatment and overall health, so it’s important to understand and discuss it with your care team.

Hypoxia means a lower-than-normal level of oxygen in the tissues. In cancer, some parts of a tumor may have low oxygen, which can make cancer cells harder to treat. Doctors may use special imaging tests to find these low-oxygen areas to help plan treatment. If you hear this term, ask your care team how it applies to your situation rather than assuming it changes your diagnosis or treatment.

Hypoxia-Inducible Factor (HIF) is a protein that helps cells respond when oxygen levels are low. Some cancer cells produce more HIF, which can help them survive, grow, and spread. If you see this term in your medical information, it’s important to ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

Hypoxic means having too little oxygen in a part of the body or tumor. In cancer care, doctors may use special imaging tests like 18F-Fluoromisonidazole PET scans to find low-oxygen areas in tumors. These areas can affect how the cancer responds to treatment. If you hear the term hypoxic, ask your care team what it means for your specific situation rather than assuming it is a diagnosis or treatment plan.

A hysterectomy is surgery to remove the uterus, sometimes along with the cervix, ovaries, and fallopian tubes. It is used to treat conditions like uterine fibroids, heavy bleeding, pain, or cancers of the uterus or cervix. After a hysterectomy, menstrual periods stop and pregnancy is no longer possible. The surgery type and recovery vary depending on the reason for the procedure.

Hytrin, also known as terazosin hydrochloride, is a medication used to treat symptoms of an enlarged prostate and high blood pressure. It works by relaxing muscles in blood vessels and the prostate to improve urine flow and lower blood pressure. Hytrin may appear under different names, so it’s important to check with your care team about what it means for your treatment.