Definitions - Glossary F thru J
This is a central location for the definitions available for many of the technical or medical words found on this site. Please click on the letters below to find definitions for words starting with that letter.
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Special thanks to the National Cancer Institute (NCI). Many of the definitions in this glossary were adapted or taken directly from the NCI's Dictionary of Cancer Terms.

ABCDEFGHIJKLMNOPQRSTUVWXYZ

fallopian tube (fa-LO-pee-in)
A slender tube through which eggs pass from an ovary to the uterus. In the female reproductive tract, there is one ovary and one fallopian tube on each side of the uterus.

false-negative test result
A test result that indicates that a person does not have a specific disease or condition when the person actually does have the disease or condition.

false-positive test result
A test result that indicates that a person has a specific disease or condition when the person actually does not have the disease or condition.

familial adenomatous polyposis (ad-in-O-mut-us pah-li-PO-sis)
FAP. An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk for colorectal cancer. Also called familial polyposis.

familial atypical multiple mole melanoma syndrome
FAMMM syndrome. An inherited condition marked by the following: (1) one or more first- or second-degree relatives (parent, sibling, child, grandparent, grandchild, aunt, or uncle) with malignant melanoma; (2) many moles, some of which are atypical (asymmetrical, raised, and/or different shades of tan, brown, black, or red) and often of different sizes; and (3) moles that have specific features when examined under a microscope. FAMMM syndrome increases the risk of melanoma and may increase the risk of pancreatic cancer.

familial cancer
Cancer that occurs in families more often than would be expected by chance. These cancers often occur at an early age, and may indicate the presence of a gene mutation that increases the risk of cancer. They may also be a sign of shared environmental or lifestyle factors.

familial dysplastic nevi (fa-MI-lee-yul dis-PLAS-tik NEE-vye)
A condition that runs in certain families in which at least two members have dysplastic nevi (atypical moles) and have a tendency to develop melanoma.

familial polyposis (pah-li-PO-sis)
An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called familial adenomatous polyposis or FAP.

family history
A record of a person's current and past illnesses, and those of his or her parents, brothers, sisters, children, and other family members. A family history shows the pattern of certain diseases in a family, and helps to determine risk factors for those and other diseases.

family therapy (FAM-ih-lee THAYR-uh-pee)
A type of therapy in which the whole family talks with a professional counselor to solve family problems.

FAMMM syndrome
Familial atypical multiple mole melanoma syndrome. An inherited condition marked by the following: (1) one or more first- or second-degree relatives (parent, sibling, child, grandparent, grandchild, aunt, or uncle) with malignant melanoma; (2) many moles, some of which are atypical (asymmetrical, raised, and/or different shades of tan, brown, black, or red) and often of different sizes; and (3) moles that have specific features when examined under a microscope. FAMMM syndrome increases the risk of melanoma and may increase the risk of pancreatic cancer.

Fanconi's anemia
A rare and often fatal inherited disease in which the bone marrow fails to produce red blood cells, white blood cells, platelets, or a combination of these cells. The disease may transform into myelodysplastic syndrome or leukemia. Also called Fanconi's syndrome.

Fanconi's syndrome
A rare and often fatal inherited disease in which the bone marrow fails to produce red blood cells, white blood cells, platelets, or a combination of these cells. The disease may transform into myelodysplastic syndrome or leukemia. Also called Fanconi anemia.

FAP
Familial adenomatous polyposis. An inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. It increases the risk of colorectal cancer. Also called familial polyposis.

Faslodex
A drug that blocks estrogen activity in the body and is used in the treatment of estrogen-dependent tumors such as breast cancer. It belongs to the family of drugs called antiestrogens. Also called fulvestrant and ICI 182780.

fast-neutron beam radiation (fast NOO-tron beem RAY-dee-AY-shun)
A type of radiation therapy that uses tiny particles called neutrons made by a machine called a cyclotron.

fatigue
A condition marked by extreme tiredness and inability to function due lack of energy. Fatigue may be acute or chronic.

fatty acid
A major component of fats that is used by the body for energy and tissue development.

fatty-replaced breast tissue
A term used in mammography that refers to the replacement of breast tissue with fatty tissue. This commonly occurs as a woman ages.

fazarabine
An anticancer drug that belongs to the family of drugs called antimetabolites.

FDA
U.S. Food and Drug Administration. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The FDA also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe.

febrile neutropenia
A condition marked by fever and decrease in the number of neutrophils in the blood. A neutrophil is a type of white blood cell that helps fight infection. Having too few neutrophils increases the risk of infection.

fecal incontinence (FEE-kal in-KAHN-tih-nens)
Inability to hold stool in the rectum.

fecal occult blood test (FEE-kul o-KULT)
FOBT. A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer.

fenretinide
A drug being studied for cancer prevention. It belongs to the family of drugs called retinoids.

fentanyl
A narcotic opioid drug that is used in the treatment of pain.

fertile (FER-tul)
Able to produce children.

fertility (fer-TIL-i-tee)
The ability to produce children.

ferumoxtran-10 (fayr-yoo-MOX-tran...)
A substance that is being studied as a way of improving magnetic resonance imaging (MRI) in diagnosing cancer and finding lymph nodes to which cancer has spread. Ferumoxtran-10 is made of nanoparticles (ultrasmall pieces) of iron oxide coated with dextran (a type of sugar). It is injected into the blood of the patient and the particles collect in lymph nodes, liver, spleen, or brain tissue where they can be seen using MRI. Ferumoxtran-10 later breaks down and passes from the body in urine.

ferumoxytol
A nanoparticle form of iron made in the laboratory that is being studied for use in iron replacement therapy, and as a contrast agent for magnetic resonance imaging. Contrast agents are substances that are injected into the body and taken up by certain tissues, making the tissues easier to see in imaging scans.

fetus (FEET-us)
The developing offspring from 7 to 8 weeks after conception until birth.

fever (FEE-ver)
An increase in body temperature above normal (98.6 degrees F), usually caused by disease.

fiber (FY-ber)
The parts of fruits, vegetables, legumes, and whole grains that cannot be digested. Fiber may help prevent cancer.

fibrin sealant
A type of surgical glue that is made from human blood-clotting proteins, and that is used during surgery to control bleeding.

fibroblast
A connective tissue cell that makes and secretes collagen proteins.

fibrocystic breast changes (FY-broh-SISS-tik)
A common condition marked by benign (noncancerous) changes in breast tissue. These changes may include irregular lumps or cysts, breast discomfort, sensitive nipples, and itching. These symptoms may change throughout the menstrual cycle and usually stop after menopause. Also called benign breast disease, fibrocystic breast disease, and mammary dysplasia.

fibrocystic breast disease (FY-broh-SISS-tik brest dih-ZEEZ )
A common condition marked by benign (noncancerous) changes in breast tissue. These changes may include irregular lumps or cysts, breast discomfort, sensitive nipples, and itching. These symptoms may change throughout the menstrual cycle and usually stop after menopause. Also called benign breast disease, fibrocystic breast changes, and mammary dysplasia.

fibroid (FYE-broyd)
A benign smooth-muscle tumor, usually in the uterus or gastrointestinal tract. Also called leiomyoma.

fibromatosis
A condition in which multiple fibromas develop. Fibromas are tumors (usually benign) that affect connective tissue.

fibrosarcoma
A type of soft tissue sarcoma that begins in fibrous tissue, which holds bones, muscles, and other organs in place.

fibrosis
The growth of fibrous tissue.

fibrous
Containing or resembling fibers.

fifth cranial nerve
The main sensory nerve of the head and face, and the motor nerve of the muscles used in chewing. Also called the trigeminal nerve.

filgrastim
A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called granulocyte colony-stimulating factor (G-CSF).

filgrastim-SD/01 (fil-GRASS-tim)
A drug used to increase numbers of white blood cells in patients who are receiving chemotherapy. It belongs to the family of drugs called colony-stimulating factors. Also called pegfilgrastim and Neulasta.

filler
An inactive substance used to make a product bigger or easier to handle. For example, fillers are often used to make pills or capsules because the amount of active drug is too small to be handled conveniently.

finasteride (fi-NAS-ta-ride)
A drug used to reduce the amount of male hormone (testosterone) produced by the body.

fine-needle aspiration (as-per-AY-shun)
The removal of tissue or fluid with a needle for examination under a microscope. Also called needle biopsy.

first-line therapy (... THAYR-uh-pee)
The first type of therapy given for a condition or disease.

fistula (fis-CHUH-luh)
An abnormal opening or passage between two organs or between an organ and the surface of the body. Fistulas may be caused by injury, infection, or inflammation, or may be created during surgery.

five element acupuncture (five EL-eh-ment AK-yoo-PUNK-cher)
An ancient form of acupuncture based on the principle that there are five universal elements (wood, fire, earth, metal, and water) that affect a person's emotions, personality, health, and response to treatment. Each person is affected by one element more than the others. Also called traditional acupuncture.

FK463
An antibiotic/antifungal drug used to treat infection.

Flagyl
A drug that is used to treat infection and is being studied in the treatment of cancer. It belongs to the families of drugs called antibacterials, antiprotozoals, and anthelmintics. Also called metronidazole.

flavonoid
A member of a group of substances found in many plants and plant-based foods. Flavonoids have shown antioxidant effects.

flavopiridol
A substance that is being studied as an anticancer drug. It belongs to the family of drugs called flavanoids.

flaxseed
The seed of the flax plant. It is a rich source of omega-3 fatty acid, fiber, and a compound called lignin. It is being studied in the prevention of prostate cancer. Also called linseed.

flecainide
A drug that is used to treat abnormal heart rhythms. It may also relieve neuropathic pain, the burning, stabbing, or stinging pain that may arise from damage to nerves caused by some types of cancer or cancer treatment.

flow cytometry
A method of measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light.

floxuridine
A drug that is used in the treatment of cancer. It belongs to the family of drugs called antimetabolites.

flt3L
A drug that increases the number of immune cells and may stimulate the immune system to kill cancer cells.

fluconazole
A drug that treats infections caused by fungi.

flucytosine
A drug that treats infections caused by fungi.

fludarabine
An anticancer drug that belongs to the family of drugs called antimetabolites.

fludeoxyglucose F 18
The radioactive form of glucose used in positron emission tomography (PET), a diagnostic imaging procedure.

fludrocortisone
A synthetic corticosteroid. It is used to replace steroid hormones normally produced by the adrenal gland.

fluid
Liquid.

fluoride
A substance that helps prevent tooth decay. Fluoride may be naturally present in or may be added to drinking water. It may also be applied to the teeth in a gel, toothpaste, or a rinse.

fluorine F 18 EF5 (FLOR-een...)
A substance that is being studied in positron emission tomography (PET) imaging to detect tumor hypoxia (a low level of oxygen in the tumor).This may help predict how the tumor will respond to treatment. It belongs to the family of drugs called radiopharmaceuticals. Also called 18F-EF5.

fluoropyrimidine
One of a group of substances used to treat cancer. Fluoropyrimidines belong to the family of drugs called antimetabolites. Examples are capecitabine, floxuridine, and fluorouracil (5-FU).

fluoroscope (FLOOR-o-skope)
An x-ray machine that makes it possible to see internal organs in motion.

fluoroscopy (floor-AHS-ko-pee)
An x-ray procedure that makes it possible to see internal organs in motion.

fluorouracil (floor-o-YOOR-a-sil)
A drug that is used as a treatment for cancer. It belongs to the family of drugs called antimetabolites. Also called 5-FU.

fluoxetine
A drug used to treat depression. It belongs to the family of drugs called antidepressants.

flutamide (FLOO-ta-mide)
An anticancer drug that belongs to the family of drugs called antiandrogens.

fluvoxamine (floo-VOX-uh-meen)
A drug used to treat obsessive-compulsive disorder. It belongs to the families of drugs called antidepressant agents and selective serotonin reuptake inhibitors (SSRIs). Also called Luvox.

FOBT
Fecal occult blood test. A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer.

focal
In terms of cancer, limited to a specific area.

folate
A B-complex vitamin that is being studied as a cancer prevention agent. Also called folic acid.

folate antagonist
A substance that blocks the activity of folic acid. Folate antagonists are used to treat cancer. Also called antifolate.

FOLFOX
An abbreviation for a type of combination chemotherapy that is used to treat colorectal cancer. It includes fluorouracil, leucovorin, and oxaliplatin.

folic acid
A B-complex vitamin that is being studied as a cancer prevention agent. Also called folate.

follicle (FOL-i-kul)
A sac or pouch-like cavity.

follicular large cell lymphoma (fo-LIK-yu-ler large cell lim-FO-ma)
A rare type of non-Hodgkin's lymphoma (cancer of the lymphatic system) with large cells that look cleaved (split) or non-cleaved under the microscope. It is an indolent (slow-growing) type of lymphoma.

follicular lymphoma (fuh-LIH-kyoo-ler lim-FOH-muh)
A type of B-cell non-Hodgkin's lymphoma (cancer of the immune system) that is usually indolent (slow-growing). The tumor cells grow as groups to form nodules. There are several subtypes of follicular lymphoma.

follicular mixed cell lymphoma (fo-LIK-yu-ler mixed cell lim-FO-ma)
An indolent (slow-growing) type of B-cell non-Hodgkin's lymphoma (cancer of the lymphatic system) in which there are both small and large cancer cells.

follicular thyroid cancer (fo-LIK-yu-ler THIGH-royd)
Cancer that develops from cells in the follicular areas of the thyroid. One of the slow-growing, highly treatable types of thyroid cancer.

follow-up
Monitoring a person's health over time after treatment. This includes keeping track of the health of people who participate in a clinical study or clinical trial for a period of time, both during the study and after the study ends.

foreskin (FOR-skin)
The loose skin that covers the head of the penis.

formaldehyde (for-MAL-duh-hide)
A chemical used in manufacturing and chemical industries, and as a preservative by anatomists, embalmers, and pathologists. Being exposed to formaldehyde may increase the risk of developing leukemia and brain cancer.

forodesine
A substance that is being studied in the treatment of some types of leukemia and lymphoma. It belongs to the family of drugs called purine nucleoside phosphorylase (PNP) enzyme inhibitors. Also called BCX-1777.

fotemustine
A substance that is being studied in the treatment of brain tumors and metastatic melanoma of the eye. It belongs to the family of drugs called nitrosoureas.

FR901228
A substance being studied in the treatment of cancer. FR901228 is a type of depsipeptide and belongs to the family of drugs called histone deacetylase inhibitors.

fractionation
Dividing the total dose of radiation therapy into several smaller, equal doses delivered over a period of several days.

fragrance (FRAY-grants)
A pleasant, sweet odor.

free radical
A highly reactive chemical that often contains oxygen and is produced when molecules are split to give products that have unpaired electrons (a process called oxidation). Free radicals can damage important cellular molecules such as DNA or lipids or other parts of the cell.

freeze-dried
A method used to dry substances, such as food, to make them last longer. The substance is frozen and then dried in a vacuum.

fulguration (ful-guh-RAY-shun)
A procedure to destroy tissue (such as a tumor) using an electric current. Also called electrofulguration.

fulvestrant (fool-VES-trant)
A drug that blocks estrogen activity in the body and is used in the treatment of estrogen-dependent tumors such as breast cancer. It belongs to the family of drugs called antiestrogens. Also called Faslodex and ICI 182780.

functional magnetic resonance imaging
A noninvasive tool used to observe functioning in the brain or other organs by detecting changes in chemical composition, blood flow, or both.

functioning tumor (FUNK-shuh-ning TOO-mer)
A tumor that is found in endocrine tissue and makes hormones (chemicals that travel in the bloodstream and control the actions of other cells or organs).

fundus
The larger part of a hollow organ that is farthest away from the organ's opening. The bladder, gallbladder, stomach, uterus, eye, and cavity of the middle ear all have a fundus.

fungating lesion
A type of skin lesion that is marked by ulcerations (breaks on the skin or surface of an organ) and necrosis (death of living tissue) and that usually has a bad smell. This kind of lesion may occur in many types of cancer, including breast cancer, melanoma, and squamous cell carcinoma, and especially in advanced disease.

fungus
A plant-like organism that does not make chlorophyll. Mushrooms, yeasts, and molds are examples. The plural is fungi.

fusion protein
A protein created by joining two genes together. Fusion proteins may occur naturally or can be created in the laboratory for research.

ABCDEFGHIJKLMNOPQRSTUVWXYZ

G-CSF
Granulocyte colony-stimulating factor. A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called filgrastim.

gabapentin
A substance that is being studied as a treatment for relieving hot flashes in women with breast cancer. It belongs to the family of drugs called anticonvulsants.

gadolinium texaphyrin
A substance that is being studied in the treatment of cancer. It may make tumor cells more sensitive to radiation therapy, improve tumor images using magnetic resonance imaging (MRI), and kill cancer cells. It belongs to the family of drugs called metalloporphyrin complexes. Also called motexafin gadolinium.

Gail model
A computer program that uses personal and family history to estimate a woman's chance of developing breast cancer.

galiximab
A monoclonal antibody that is being studied in the treatment of follicular non-Hodgkin's lymphoma. Monoclonal antibodies are made in the laboratory and can locate and bind to cancer cells. Galiximab binds to the protein CD80, which is found on certain normal and cancerous white blood cells.

gallbladder (GAWL-blad-er)
The pear-shaped organ found below the liver. Bile is concentrated and stored in the gallbladder.

gallbladder cancer (GAWL-bla-der KAN-ser)
Cancer that forms in tissues of the gallbladder. The gallbladder is a pear-shaped organ below the liver that collects and stores bile (a fluid made by the liver to digest fat). Gallbladder cancer begins in the innermost layer of tissue and spreads through the outer layers as it grows.

gallium nitrate
A drug that lowers blood calcium. Used as treatment for hypercalcemia (too much calcium in the blood) and for cancer that has spread to the bone (bone metastases).

gallium scan
A procedure to detect areas of the body where cells are dividing rapidly. It is used to locate cancer cells or areas of inflammation. A very small amount of radioactive gallium is injected into a vein and travels through the bloodstream. The gallium is taken up by rapidly dividing cells in the bones, tissues, and organs and is detected by a scanner.

gallstone
Solid material that forms in the gallbladder or common bile duct. Gallstones are made of cholesterol or other substances found in the gallbladder. They may occur as one large stone or as many small ones, and vary from the size of a golf ball to a grain of sand. Also called cholelith.

gamma irradiation
A type of radiation therapy that uses gamma radiation. Gamma radiation is a type of high-energy radiation that is different from x-rays.

gamma knife
Radiation therapy in which high-energy rays are aimed at a tumor from many angles in a single treatment session.

gamma ray
A type of high-energy radiation that is different from an x-ray.

gamma scanning (GA-muh SKAN-ing)
A procedure to find areas in the body where cells, such as tumor cells, are dividing rapidly. A small amount of radioactive material is injected into a vein or swallowed, and travels through the bloodstream. A machine called a scanner measures the radioactivity and produces pictures (scans) of internal parts of the body. The pictures can show abnormal changes in the area of the body containing the radioactive material. Examples of gamma scans include PET scans, gallium scans, and bone scans. Also called radionuclide scanning.

ganciclovir
An antiviral agent used to prevent or treat cytomegalovirus infections that may occur when the body's immune system is suppressed. In gene therapy, ganciclovir is used with an altered herpes simplex virus-1 gene to kill advanced melanoma cells and brain tumor cells.

ganglioside
A complex molecule that contains both lipids (fats) and carbohydrates (sugars) and is found in the plasma (outer) membrane of many kinds of cells. Several different types of gangliosides have been identified.

garden heliotrope
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, garden valerian, Indian valerian, Pacific valerian, Mexican valerian, and Valerianae radix.

garden valerian
Valeriana officinalis. A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called valerian, Indian valerian, Pacific valerian, Mexican valerian, garden heliotrope, and Valerianae radix.

garlic (GAR-lik)
Allium sativum. A European plant that has a bulb used to flavor food. It has also been used in some cultures to treat certain medical conditions including high cholesterol, high blood pressure, infections, and cancer.

gastrectomy (gas-TREK-tuh-mee)
An operation to remove all or part of the stomach.

gastric (GAS-trik)
Having to do with the stomach.

gastric atrophy (GAS-trik AT-ro-fee)
A condition in which the stomach muscles shrink and become weak. The digestive (peptic) glands may also shrink, resulting in a lack of digestive juices.

gastric cancer (GAS-trik KAN-ser)
Cancer that forms in tissues lining the stomach. Also called stomach cancer.

gastric reflux
The backward flow of stomach acid contents into the esophagus (the tube that connects the mouth to the stomach). Also called esophageal reflux or gastroesophageal reflux.

gastrin (GAS-trin)
A group of hormones released after eating that control the amount of acid in the stomach.

gastrinoma (gas-tri-NO-ma)
A tumor that causes overproduction of gastric acid. It usually occurs in the islet cells of the pancreas but may also occur in the esophagus, stomach, spleen, or lymph nodes.

gastritis
Inflammation of the lining of the stomach.

gastroenterologist (GAS-tro-en-ter-AHL-o-jist)
A doctor who specializes in diagnosing and treating disorders of the digestive system.

gastroesophageal junction
The place where the esophagus is connected to the stomach.

gastroesophageal reflux (GAS-tro-ee-sof-uh-JEE-ul REE-flux)
The backward flow of stomach acid contents into the esophagus (the tube that connects the mouth to the stomach). Also called esophageal reflux or gastric reflux.

gastrointestinal (GAS-tro-in-TES-tih-nul)
GI. Refers to the stomach and intestines.

gastrointestinal carcinoid tumor (GAS-troh-in-TES-tih-nul KAR-sih-noyd TOO-mer)
An indolent (slow-growing) cancer that forms in cells that make hormones in the lining of the gastrointestinal tract (the stomach and intestines). It usually occurs in the appendix (a small fingerlike pouch of the large intestine), small intestine, or rectum. Having gastrointestinal carcinoid tumor increases the risk of forming other cancers of the digestive system.

gastrointestinal stromal tumor
GIST. A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. It can be benign or malignant.

gastrointestinal tract (GAS-tro-in-TES-tih-nul)
The stomach and intestines.

gastroscope (GASS-troh-SKOPE)
A thin, tube-like instrument used to examine the inside of the stomach. A gastroscope has a light and a lens for viewing and may have a tool to remove tissue.

gastroscopy (gass-TROSS-koh-pee)
Examination of the inside of the stomach using a gastroscope passed through the mouth and esophagus. A gastroscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called upper endoscopy.

gefitinib (geh-FIT-in-ib)
A drug that is used to treat non-small cell lung cancer and is being studied in the treatment of other types of cancer. It belongs to the family of drugs called epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors. Also called ZD1839.

geldanamycin analog
An antineoplastic antibiotic drug that belongs to the family of drugs called ansamycins.

GEM 231
A drug that may inhibit the growth of malignant tumors.

gemcitabine
An anticancer drug that belongs to the family of drugs called antimetabolites.

gemtuzumab ozogamicin
A type of monoclonal antibody used in cancer detection or therapy. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells.

Genasense
A substance that is being studied in the treatment of cancer. It may kill cancer cells by blocking the production of a protein that makes cancer cells live longer and by making them more sensitive to anticancer drugs. It belongs to the family of drugs called antisense oligodeoxyribonucleotides. Also called oblimersen, augmerosen, and bcl-2 antisense oligodeoxynucleotide G3139.

gene
The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

gene deletion
The total loss or absence of a gene.

gene expression profiling
A research method that measures messenger RNA made from many different genes in various cell types. It is being used as a diagnostic test to help identify subgroups of tumor types, to help predict which patients may respond to treatment, and which patients may be at increased risk for cancer relapse.

gene therapy (jeen THAYR-uh-pee)
Treatment that alters a gene. In studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to fight the disease or to make the cancer cells more sensitive to other kinds of therapy.

gene transfer
The insertion of genetic material into a cell.

gene-modified
Cells that have been altered to contain different genetic material than they originally contained.

general anesthesia (an-es-THEE-zha)
Drugs that cause loss of feeling or awareness and put the person to sleep.

generic
Official nonbrand names by which medicines are known. Generic names usually refer to the chemical name of the drug.

genetic
Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

genetic analysis
The study of a sample of DNA to look for mutations (changes) that may increase risk of disease or affect the way a person responds to treatment.

genetic counseling
A communication process between a specially trained health professional and a person concerned about the genetic risk of disease. The person's family and personal medical history may be discussed, and counseling may lead to genetic testing.

genetic marker
Alteration in DNA that may indicate an increased risk of developing a specific disease or disorder.

genetic susceptibility
An inherited increase in the risk of developing a disease.

genetic testing
Analyzing DNA to look for a genetic alteration that may indicate an increased risk for developing a specific disease or disorder.

genetics (jeh-NEH-tiks)
The study of genes and heredity. Heredity is the passing of genetic information and traits (such as eye color and an increased chance of getting a certain disease) from parents to offspring.

genistein
An isoflavone found in soy products. Soy isoflavones are being studied to see if they help prevent cancer.

genital wart
A raised growth on the surface of the genitals caused by human papillomavirus (HPV) infection. The HPV in genital warts is very contagious and can be spread by skin-to-skin contact, usually during oral, anal, or genital sex with an infected partner. A female with genital warts is at an increased risk for developing cervical cancer. Also called condyloma and condylomata acuminata.

genitourinary system (GEN-ih-toe-YOO-rin-air-ee)
The parts of the body that play a role in reproduction, getting rid of waste products in the form of urine, or both.

genome
The complete genetic material of an organism.

genomics (jeh-NOH-miks)
The study of the complete genetic material, including genes and their functions, of an organism.

germ cell
A reproductive cell of the body. Germ cells are egg cells in females and sperm cells in males.

germ cell tumor
A type of tumor that begins in the cells that give rise to sperm or eggs. Germ cell tumors can occur almost anywhere in the body and can be either benign or malignant.

germ-free
Free of bacteria, disease-causing viruses, and other organisms that can cause infection.

German chamomile (JER-mun KA-moh-MY-ul)
A plant with daisy-like flowers that are used in tea to calm and relax, improve sleep, and help stomach problems. German chamomile has been studied in the prevention of mucositis (mouth sores) caused by chemotherapy and radiation therapy. It has also been used in some cultures to treat skin conditions, mild infections, and other disorders. The scientific name is Matricaria recutita.

German Commission E
The German Federal Institute for Drugs and Medical Devices Commission E. A committee made up of scientists, toxicologists, doctors, and pharmacists formed by the German government in 1978 to find out if herbs sold in Germany are safe and effective. The Commission has published information on the uses, side effects, and drug interactions of more than 300 herbs.

germinoma (jer-mih-NO-ma)
The most common type of germ cell tumor in the brain.

germline mutation
A gene change in the body's reproductive cells (egg or sperm) that becomes incorporated into the DNA of every cell in the body of offspring; germline mutations are passed on from parents to offspring. Also called hereditary mutation.

Gerota's capsule
A fibrous envelope of tissue that surrounds the kidney. Also called renal fascia and Gerota's fascia.

Gerota's fascia (Ga-RO-tahz FAYSH-ee-uh)
A fibrous envelope of tissue that surrounds the kidney. Also called renal fascia and Gerota's capsule.

Gerson therapy
A diet plan that has been claimed to be a treatment for cancer, migraine, tuberculosis, and other diseases. It is a vegetarian diet that includes eating organic fruits and vegetables and 13 glasses of fresh juice each day. It also includes supplements with iodine, vitamin B-12, potassium, thyroid hormone, liver extract, and pancreatic enzymes. No clinical trial to test Gerson therapy has been reported.

gestational trophoblastic disease
A rare cancer in women of childbearing age in which cancer cells grow in the tissues that are formed in the uterus after conception. Also called gestational trophoblastic tumor, gestational trophoblastic neoplasia, molar pregnancy, or choriocarcinoma.

gestational trophoblastic neoplasia
A rare cancer in women of childbearing age in which cancer cells grow in the tissues that are formed in the uterus after conception. Also called gestational trophoblastic disease, gestational trophoblastic tumor, molar pregnancy, or choriocarcinoma.

gestational trophoblastic tumor
A rare cancer in women of childbearing age in which cancer cells grow in the tissues that are formed in the uterus after conception. Also called gestational trophoblastic disease, gestational trophoblastic neoplasia, molar pregnancy, or choriocarcinoma.

GI14721
An antitumor drug that belongs to the family of drugs called topoisomerase inhibitors. It is a camptothecin analog.

giant cell fibroblastoma
A rare type of soft tissue tumor marked by painless nodules in the dermis (the inner layer of the two main layers of tissue that make up the skin) and subcutaneous (beneath the skin) tissue. These tumors may come back after surgery, but they do not spread to other parts of the body. They occur mostly in boys and are related to dermatofibrosarcoma protuberans.

gimatecan
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called topoisomerase inhibitors. Also called ST1481.

ginger
Zingiber officianale. An herb with a root that has been used in cooking, and by some cultures to treat nausea, vomiting, and certain other medical conditions. It is being studied in the treatment of nausea and vomiting caused by cancer chemotherapy.

gingiva (JIN-jih-vuh)
The tissue of the upper and lower jaws that surrounds the base of the teeth. Also called gums.

ginkgo (GING-koh)
A tree native to China. Substances taken from the leaves and seeds have been used in some cultures to treat certain medical problems. Ginkgo has been studied in the prevention and treatment of Alzheimer's disease, dementia, certain blood vessel diseases, and memory loss. It may cause bleeding or high blood pressure when used with certain drugs. Also called ginkgo biloba and maidenhair tree.

ginkgo biloba (GING-koh BY-LOH-buh)
A tree native to China. Substances taken from the leaves and seeds have been used in some cultures to treat certain medical problems. Ginkgo biloba has been studied in the prevention and treatment of Alzheimer's disease, dementia, certain blood vessel diseases, and memory loss. It may cause bleeding or high blood pressure when used with certain drugs. Also called ginkgo and maidenhair tree.

ginseng
An herb with a root that has been used in some cultures to treat certain medical problems. It may have anticancer effects.

GIST
Gastrointestinal stromal tumor. A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. It can be benign or malignant.

gland
An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Endocrine glands release the substances directly into the bloodstream. Exocrine glands release the substances into a duct or opening to the inside or outside of the body.

glans penis
The rounded, gland-like head of the penis.

Gleason score (GLEE-sun...)
A system of grading prostate cancer tissue based on how it looks under a microscope. Gleason scores range from 2 to 10 and indicate how likely it is that a tumor will spread. A low Gleason score means the cancer tissue is similar to normal prostate tissue and the tumor is less likely to spread; a high Gleason score means the cancer tissue is very different from normal and the tumor is more likely to spread.

Gleevec (GLEE-vek)
A drug that is used to treat gastrointestinal stromal tumors and certain types of chronic myelogenous leukemia. It is also being studied in the treatment of other types of cancer. Imatinib mesylate blocks a protein made by the bcr/abl oncogene. It belongs to the family of drugs called tyrosine kinase inhibitors. Also called imatinib mesylate and STI571.

Gliadel Wafer
A biodegradable wafer that is used to deliver the anticancer drug carmustine directly into a brain tumor site after the tumor has been removed by surgery. Also called polifeprosan 20 carmustine implant.

glial cell (GLEE-al)
A type of cell that surrounds nerve cells and holds them in place. Glial cells also insulate nerve cells from each other.

glial tumor
A general term for tumors of the central nervous system, including astrocytomas, ependymal tumors, glioblastoma multiforme, and primitive neuroectodermal tumors.

glioblastoma (glee-o-blas-TOE-ma)
A general term that refers to malignant astrocytoma, a type of brain tumor.

glioblastoma multiforme (glee-o-blas-TOE-ma mul-tih-FOR-may)
A type of brain tumor that forms from glial (supportive) tissue of the brain. It grows very quickly and has cells that look very different from normal cells. Also called grade IV astrocytoma.

glioma (glee-O-ma)
A cancer of the brain that begins in glial cells (cells that surround and support nerve cells).

gliosarcoma
A type of glioma (cancer of the brain that comes from glial, or supportive, cells).

glossectomy
Surgical removal of all or part of the tongue.

glottis (GLAH-tis)
The middle part of the larynx; the area where the vocal cords are located.

glucagon
A hormone produced by the pancreas that increases the level of glucose (sugar) in the blood.

glucagonoma (GLOO-kuh-guh-NO-ma)
A rare pancreatic tumor that produces a hormone called glucagon. Glucagonomas can produce symptoms similar to diabetes.

glucocorticoid
A compound that belongs to the family of compounds called corticosteroids (steroids). Glucocorticoids affect metabolism and have anti-inflammatory and immunosuppressive effects. They may be naturally produced (hormones) or synthetic (drugs).

gluconeogenesis
The process of making glucose (sugar) from its own breakdown products or from the breakdown products of lipids (fats) or proteins. Gluconeogenesis occurs mainly in cells of the liver or kidney.

glucose
A type of sugar; the chief source of energy for living organisms.

glufosfamide
An anticancer drug that belongs to the family of drugs called alkylating agents.

glutamine
An amino acid used in nutrition therapy. It is also being studied for the treatment of diarrhea caused by radiation therapy to the pelvis.

glutathione
A substance found in plant and animal tissues that has many functions in a cell. These include activating certain enzymes and destroying toxic compounds and chemicals that contain oxygen.

glutathione S-transferase
A family of enzymes involved in metabolism and in making toxic compounds less harmful to the body.

glycinamide ribonucleotide formyltransferase inhibitor
A drug that blocks DNA synthesis and may prevent tumor growth. It is being studied as a treatment for cancer.

Glycine max
A plant of Asian origin that produces beans used in many food products. Soy products contain isoflavones (estrogen-like substances) that are being studied for the prevention of cancer, hot flashes that occur with menopause, and osteoporosis (loss of bone density). Soy products in the diet may lower cholesterol levels and reduce the risk of heart disease. Also called soy, soya, and soybean.

glycolysis
A process in which glucose (sugar) is partially broken down by cells in enzyme reactions that do not need oxygen. Glycolysis is one method that cells use to produce energy. When glycolysis is linked with other enzyme reactions that use oxygen, more complete breakdown of glucose is possible and more energy is produced.

glycopeptide
A short chain of amino acids (the building blocks of proteins) that has sugar molecules attached to it. Some glycopeptides have been studied for their ability to stimulate the immune system.

glycoprotein
A protein that has sugar molecules attached to it.

glycoprotein 100
gp100. A tumor-specific antigen used in the development of cancer vaccines.

glycosaminoglycan
A type of long, unbranched polysaccharide molecule. Glycosaminoglycans are major structural components of cartilage and are also found in the cornea of the eye.

GM-CSF
Granulocyte-macrophage colony-stimulating factor. A substance that helps make more white blood cells, especially granulocytes, macrophages, and cells that become platelets. It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called sargramostim.

GM2-KLH vaccine
A substance used to stimulate the production of antibodies that fight certain cancer cells.

GnRH
Gonadotropin-releasing hormone. A hormone made by the hypothalamus (part of the brain). GnRH causes the pituitary gland to make luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones are involved in reproduction.

goiter
An enlarged thyroid. It may be caused by too little iodine in the diet or by other conditions. Most goiters are not cancer.

gonad
The part of the reproductive system that produces and releases eggs (ovary) or sperm (testicle/testis).

gonadotropin-releasing hormone
GnRH. A hormone made by the hypothalamus (part of the brain). GnRH causes the pituitary gland to make luteinizing hormone (LH) and follicle stimulating hormone (FSH). These hormones are involved in reproduction.

gonadotropin-releasing hormone agonist
A hormone made in the laboratory that has the same effect as the gonadotropin-releasing hormone (GnRH) produced naturally by the body.

Gonzalez regimen
An alternative therapy that is being studied as a treatment for pancreatic cancer. It includes a special diet, nutritional supplements, pancreatic enzymes, and coffee enemas.

Gorlin syndrome
A genetic condition that causes unusual facial features and disorders of the skin, bones, nervous system, eyes, and endocrine glands. People with this syndrome have a higher risk of basal cell carcinoma. Also called nevoid basal cell carcinoma syndrome and basal cell nevus syndrome.

goserelin (go-SAIR-uh-lin)
A drug that belongs to the family of drugs called gonadotropin-releasing hormone analogs. Goserelin is used to block hormone production in the ovaries or testicles.

gossypol
An anticancer drug extracted from the cotton plant.

gp100
Glycoprotein 100. A tumor-specific antigen used in the development of cancer vaccines.

gp209-2M
A peptide (short piece of protein) made from the tumor-specific antigen gp100, and used to make vaccines being studied in the treatment of melanoma.

GPX-100
An anticancer drug that belongs to the family of drugs called antitumor antibiotics. It is an anthracycline.

grade
The grade of a tumor depends on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Grading systems are different for each type of cancer.

grade 1 follicular lymphoma (fuh-LIH-kyoo-ler lim-FOH-muh)
An indolent (slow-growing) type of non-Hodgkin's lymphoma marked by enlarged lymph nodes and small cells that have cleaved (u-shaped) nuclei.

grade 2 follicular lymphoma (fuh-LIH-kyoo-ler lim-FOH-muh)
An indolent (slow-growing) type of non-Hodgkin's lymphoma marked by enlarged lymph nodes and a mix of large cells and small cells that have cleaved (u-shaped) nuclei.

grade 3 follicular lymphoma (fuh-LIH-kyoo-ler lim-FOH-muh)
A type of non-Hodgkin's lymphoma marked by large cells and enlarged lymph nodes. Grade 3 follicular lymphoma is less common, and more aggressive than grades 1 or 2 follicular lymphoma.

grade IV astrocytoma
A type of brain tumor that forms from glial (supportive) tissue of the brain. It grows very quickly and has cells that look very different from normal cells. Also called glioblastoma multiforme.

grading
A system for classifying cancer cells in terms of how abnormal they appear when examined under a microscope. The objective of a grading system is to provide information about the probable growth rate of the tumor and its tendency to spread. The systems used to grade tumors vary with each type of cancer. Grading plays a role in treatment decisions.

graft
Healthy skin, bone, or other tissue taken from one part of the body and used to replace diseased or injured tissue removed from another part of the body.

graft-versus-host disease
GVHD. A reaction of donated stem cells against the patient's tissue.

graft-versus-tumor
An immune response to a person's tumor cells by immune cells present in a donor's transplanted tissue, such as bone marrow or peripheral blood.

gram
A unit of weight in the metric system. One gram is equal to one thousandth of a kilogram and is approximately 30-times less than an ounce.

granisetron
A drug that prevents or reduces nausea and vomiting. It belongs to the family of drugs called antiemetics.

granulocyte (GRAN-yoo-lo-site)
A type of white blood cell that fights bacterial infection. Neutrophils, eosinophils, and basophils are granulocytes.

granulocyte colony-stimulating factor
G-CSF. A colony-stimulating factor that stimulates the production of neutrophils (a type of white blood cell). It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called filgrastim.

granulocyte-macrophage colony-stimulating factor (GRAN-yoo-loh-SITE MA-kruh-FAYJ KAH-luh-nee STIM-yoo-LAY-ting FAK-ter)
GM-CSF. A substance that helps make more white blood cells, especially granulocytes, macrophages, and cells that become platelets. It is a cytokine that belongs to the family of drugs called hematopoietic (blood-forming) agents. Also called sargramostim.

granulocytic sarcoma
A malignant, green-colored tumor of myeloid cells (a type of immature white blood cell). This tumor is usually associated with myelogenous leukemia. Also called chloroma.

granulocytopenia
A deficiency in the number of granulocytes, a type of white blood cell.

granulosa cell tumor
A type of slow-growing, malignant tumor that usually affects the ovary.

gray elm
Ulmus fulva or Ulmus rubra. The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called slippery elm, Indian elm, red elm, and sweet elm.

green tea extract
A substance that is being studied in the prevention of cancer. It is made from decaffeinated green tea, and contains chemicals called catechins, which are antioxidants. Also called Polyphenon R E.

Greene Menopause Index
A tool used by researchers to study the symptoms of menopause. It is a standard list of 21 questions which women use to rate how much they are bothered by menopause symptoms such as hot flashes, night sweats, rapid heartbeat, and difficulty sleeping.

groin
The area where the thigh meets the abdomen.

growth factor
A substance made by the body that functions to regulate cell division and cell survival. Some growth factors are also produced in the laboratory and used in biological therapy.

GTI-2040
A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called antisense oligonucleotides.

gums
The tissue of the upper and lower jaws that surrounds the base of the teeth. Also called gingiva.

GVHD
Graft-versus-host disease. A reaction of donated stem cells against the patient's tissue.

GW572016
A substance that is being studied in the treatment of cancer. It belongs to the family of drugs called ErbB-2 and EGFR dual tyrosine kinase inhibitors. Also called lapatinib and Tykerb.

GW786034
A substance that is being studied as a treatment for cancer. It belongs to the families of drugs called protein tyrosine kinase inhibitors and angiogenesis inhibitors.

gynecologic
Having to do with the female reproductive tract (including the cervix, endometrium, fallopian tubes, ovaries, uterus, and vagina).

gynecologic cancer (guy-neh-ko-LAH-jik)
Cancer of the female reproductive tract, including the cervix, endometrium, fallopian tubes, ovaries, uterus, and vagina.

gynecologic oncologist (guy-neh-ko-LAH-jik on-KOL-o-jist)
A doctor who specializes in treating cancers of the female reproductive organs.

gynecologist (guy-neh-KAH-lo-jist)
A doctor who specializes in treating diseases of the female reproductive organs.

ABCDEFGHIJKLMNOPQRSTUVWXYZ


H. pylori
Helicobacter pylori. A type of bacteria that causes inflammation and ulcers in the stomach or small intestine. People with H. pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma.

hA20
A monoclonal antibody that is being studied in the treatment of refractory B-cell non-Hodgkin's lymphoma. Monoclonal antibodies are made in the laboratory and can locate and bind to cancer cells. hA20 binds to the protein CD20, which is found on B cells (a type of immune system cell), and some types of lymphoma cells. Also called IMMU-106 and HCD20.

HAART
Highly active antiretroviral therapy. Treatment for human immunodeficiency virus (HIV) infection that uses a combination of several antiretroviral drugs. The drugs inhibit the ability of the virus to multiply in the body, and they slow down the development of AIDS.

hair follicle (FOL-i-kul)
A shaft or opening on the surface of the skin through which hair grows.

hairy cell leukemia
A rare type of leukemia in which abnormal B-lymphocytes (a type of white blood cell) are present in the bone marrow, spleen, and peripheral blood. When viewed under a microscope, these cells appear to be covered with tiny hair-like projections.

halofuginone hydrobromide
A substance that is being studied for its ability to slow the growth of connective tissue and prevent the growth of new blood vessels to a solid tumor. It belongs to the family of drugs called quinazolinone alkaloids.

Halsted radical mastectomy
Surgery for breast cancer in which the breast, chest muscles, and all of the lymph nodes under the arm are removed. For many years, this was the breast cancer operation used most often, but it is used rarely now. Doctors consider radical mastectomy only when the tumor has spread to the chest muscles. Also called radical mastectomy.

hamartoma (ham-ar-TOE-ma)
A benign (noncancerous) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs.

hand-foot syndrome
A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also known as palmar-plantar erythodysthesia.

happy major
Arctium lappa. A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called burdock and lappa.

hard palate (PAL-et)
The front, bony part of the roof of the mouth.

hawthorn fruit
The fruit of the hawthorn tree or bush. It has been used in some cultures to treat certain medical problems, including heart problems and gastrointestinal problems.

HCA
Heterocyclic amine. A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. HCAs are carcinogens (substances that may cause cancer).

HCD20
A monoclonal antibody that is being studied in the treatment of refractory B-cell non-Hodgkin's lymphoma. Monoclonal antibodies are made in the laboratory and can locate and bind to cancer cells. HCD20 binds to the protein CD20, which is found on B cells (a type of immune system cell), and some types of lymphoma cells. Also called IMMU-106 and hA20.

HCP
Healthcare proxy. A type of advance directive that gives a person (such as a relative, lawyer, or friend) the authority to make healthcare decisions for another person. It becomes active when that person loses the ability to make decisions for himself or herself.

hCRF
Human corticotropin-releasing factor. A substance that is being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. hCRF may help reduce symptoms caused by edema (swelling) of the brain. It belongs to the family of drugs called neurohormones.

HDAC inhibitor (...in-HIH-bih-ter)
Histone deacetylase inhibitor. A substance that causes a chemical change that stops tumor cells from dividing. HDAC inhibitors are being studied in the treatment of cancer.

HDR
High-dose radiation. An amount of radiation that is greater than that given in typical radiation therapy. HDR is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments.

head and neck cancer
Cancer that arises in the head or neck region (in the nasal cavity, sinuses, lip, mouth, salivary glands, throat, or larynx [voice box]).

healthcare proxy
HCP. A type of advance directive that gives a person (such as a relative, lawyer, or friend) the authority to make healthcare decisions for another person. It becomes active when that person loses the ability to make decisions for himself or herself.

heart cancer (hart KAN-ser)
A rare cancer that develops in tissues of the heart. Also called cardiac sarcoma.

Hedyotis diffusa
An herb used in traditional Chinese medicine to treat certain medical problems. It has been used to boost the immune system and may have anticancer effects.

helical computed tomography
A detailed picture of areas inside the body. The pictures are created by a computer linked to an x-ray machine that scans the body in a spiral path. Also called spiral CT scan.

Helicobacter pylori (HEEL-ih-koh-BAK-ter py-LOR-ee)
H. pylori. A type of bacteria that causes inflammation and ulcers in the stomach or small intestine. People with H. pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma.

helper T cell
A type of white blood cell that helps stimulate immune system reactions. Helper T cells help activate cytotoxic T cells and macrophages by secreting cytokines. They also stimulate B cells to make antibodies.

hemagglutinin-neuraminidase
A protein found in the outer coat of paramyxoviruses. This protein helps virus particles bind to cells, making infection easier.

hemangiopericytoma
A type of cancer involving blood vessels and soft tissue.

hemangiosarcoma
A type of cancer that begins in the cells that line blood vessels.

hematogenous
Originating in the blood or spread through the bloodstream.

hematologic malignancy
A cancer of the blood or bone marrow, such as leukemia or lymphoma. Also called hematologic cancer.

hematologist (hee-muh-TOL-o-jist)
A doctor who specializes in treating blood disorders.

hematoma (hee-muh-TOH-muh)
A pool of clotted or partially clotted blood in an organ, tissue, or body space, usually caused by a broken blood vessel.

hematopoiesis
The forming of new blood cells.

hematopoietic growth factor
A group of proteins that causes blood cells to grow and mature.

hematopoietic tissue
Tissue in which new blood cells are formed.

hematoporphyrin derivative
A drug used in photodynamic therapy that is absorbed by tumor cells. When exposed to light, it becomes active and kills the cancer cells.

hematuria (HEE-muh-TOOR-ee-uh)
Blood in the urine.

hemilaryngectomy (HEM-ee-LAIR-in-JEK-tuh-mee)
An operation to remove one side of the larynx (voicebox).

hemochromatosis (HEE-moh-kroh-muh-TOH-sis)
A condition in which the body absorbs more iron from food than it needs. The extra iron is stored in and may damage the liver, heart, and pancreas. It may cause organ failure, cancer, heart problems, and liver disease. Hemochromatosis may also cause bronze skin, diabetes, pain in the joints and abdomen, tiredness, and impotence.

hemoglobin (HE-muh-GLOW-bun)
The substance inside red blood cells that binds to oxygen and carries it from the lungs to the tissues.

hemophilia
Group of hereditary disorders in which affected individuals fail to make enough of certain proteins needed to form blood clots.

hemoptysis (hee-MOP-tih-sis)
Coughing or spitting up blood from the respiratory tract.

hemorrhage
In medicine, loss of blood from damaged blood vessels. A hemorrhage may be internal or external, and usually involves a lot of bleeding in a short time.

hemorrhoid (HEM-uh-roid)
An enlarged or swollen blood vessel, usually located near the anus or the rectum.

heparin
A drug that helps prevent blood clots from forming. It belongs to the family of drugs called anticoagulants (blood thinners).

hepatectomy
Surgery to remove all or part of the liver.

hepatic
Refers to the liver.

hepatic arterial infusion
A procedure to deliver chemotherapy directly to the liver. Catheters are put into an artery in the groin that leads directly to the liver, and drugs are given through the catheters.

hepatic arterial occlusion (heh-PA-tik ar-TEER-ee-ul uh-KLOO-zhun)
A block in blood flow to the liver. It can happen while giving chemotherapy through a catheter in the hepatic artery. Sometimes doctors use drugs or other agents to cause hepatic arterial occlusion on purpose. This block of blood flow to the liver helps kill cancer cells growing in the liver.

hepatic artery
The major blood vessel that carries blood to the liver.

hepatic portal vein
A blood vessel that carries blood to the liver from the stomach, small and large intestines, spleen, pancreas, and gallbladder. Also called portal vein.

hepatic veno-occlusive disease
A condition in which some of the veins in the liver are blocked. It is sometimes a complication of high-dose chemotherapy given before a bone marrow transplant and is marked by increases in weight, liver size, and blood levels of bilirubin.

hepatitis (hep-a-TYE-tis)
Disease of the liver causing inflammation. Symptoms include an enlarged liver, fever, nausea, vomiting, abdominal pain, and dark urine.

hepatitis A vaccine (HEH-puh-TY-tis AY vak-SEEN)
A vaccine used to prevent infection with the hepatitis A virus, which causes a serious liver disease. The vaccine is made of a weakened form of the virus that cannot cause disease but causes the body's immune system to make antibodies that destroy the hepatitis A virus.

hepatitis A virus (HEH-puh-TY-tis AY VY-rus)
A virus that causes a serious liver disease. It is usually spread by contact with an infected person's stool by eating food he or she has handled after not washing hands, but it can be spread in other ways. Symptoms of infection include jaundice, dark urine, and fever and other flu-like symptoms.

hepatitis B virus
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through blood or sexual contact. Also, infants born to infected mothers may become infected with the virus.

hepatitis C virus
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through blood or sexual contact. Also, infants born to infected mothers may become infected with the virus.

hepatobiliary
Having to do with the liver, bile ducts, and/or gallbladder.

hepatoblastoma (HEP-a-toe-blas-TOE-ma)
A type of liver tumor that occurs in infants and children.

hepatocellular carcinoma (HEP-a-toe-SEL-yoo-ler KAR-sih-NOH-muh)
A type of adenocarcinoma, the most common type of liver tumor.

hepatocyte (HEP-a-toe-site)
A liver cell.

hepatoma (hep-a-TOE-ma)
A liver tumor.

hepatomegaly
Enlarged liver.

HER1
Epidermal growth factor receptor. The protein found on the surface of some cells and to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, so these cells may divide excessively in the presence of epidermal growth factor. Also known as EGFR or ErbB1.

HER2/neu
Human epidermal growth factor receptor 2. The HER2/neu protein is involved in the growth of some cancer cells. Also called c-erbB-2.

HER2/neu gene
The gene that makes the human epidermal growth factor receptor 2. The protein produced is HER2/neu, which is involved in the growth of some cancer cells. Also called c-erbB-2.

herba scutellaria barbatae
An herb used in traditional Chinese medicine to treat certain medical problems. It may have anticancer effects.

herbal (ER-bul)
Having to do with plants.

herbal medicine (ER-bul MEH-dih-sin)
A type of medicine that uses roots, stems, leaves, flowers, or seeds of plants to improve health, prevent disease, and treat illness.

herbicide
A chemical that kills plants.

Herceptin (her-SEP-tin)
A type of monoclonal antibody used to detect or treat some types of cancer. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells. Herceptin blocks the effects of the growth factor protein HER2, which transmits growth signals to breast cancer cells. Also called trastuzumab.

hereditary (ha-RED-ih-tair-ee)
Transmitted from parent to child by information contained in the genes.

hereditary leiomyomatosis and renal cell cancer syndrome
HLRCC. A rare inherited disorder that increases the risk of developing benign (noncancerous) tumors of the skin and the uterus (leiomyomas) and malignant (cancerous) tumors of the uterus (leiomyosarcoma) and the kidney.

hereditary mutation
A gene change in the body's reproductive cells (egg or sperm) that becomes incorporated into the DNA of every cell in the body of offspring; hereditary mutations are passed on from parents to offspring. Also called germline mutation.

hereditary nonpolyposis colon cancer
HNPCC. An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, often before the age of 50. Also called Lynch syndrome.

herpesvirus (HER-peez-VYE-rus)
A member of the herpes family of viruses.

heterocyclic amine (HEH-tuh-roh-SY-klik A-meen)
HCA. A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. HCAs are carcinogens (substances that may cause cancer).

heterogeneous
Made up of elements or ingredients that are not alike.

heterogenic (het-er-o-JEN-ik)
Derived from a different source or species. Also called heterogenous.

heterogenous
Derived from a different source or species. Also called heterogenic.

hexyl 5-aminolevulinate
A substance that is used to find and kill tumor cells. It enters tumor cells and becomes activated when exposed to a special type of light. A chemical reaction causes the cells to produce fluorescent light and die.

HHV8
Human herpesvirus 8. A type of herpesvirus that may cause Kaposi's sarcoma (a rare cancer that can cause skin lesions) and a type of lymphoma (cancer that begins in the lymph system), especially in patients who have a weak immune system. Also called Kaposi's sarcoma-associated herpesvirus (KSHV).

high blood pressure (hy blud PREH-shur)
A blood pressure of 140/90 or higher. High blood pressure usually has no symptoms. It can harm the arteries and cause an increase in the risk of stroke, heart attack, kidney failure, and blindness. Also called hypertension.

high grade
When referring to cancerous and precancerous growths, a term used to describe cells that look abnormal under a microscope. These cells are more likely to grow and spread quickly than cells in low-grade cancerous and precancerous growths.

high-dose chemotherapy (hy-dose kee-moh-THAYR-uh-pee)
An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects. High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.

high-dose radiation (hy-dose RAY-dee-AY-shun)
HDR. An amount of radiation that is greater than that given in typical radiation therapy. HDR is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments.

high-dose-rate remote brachytherapy (hy-dose-rate ree-MOTE BRAY-kee-THAYR-uh-pee)
A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote radiation therapy or remote brachytherapy.

high-dose-rate remote radiation therapy (hy-dose-rate ree-MOTE RAY-dee-AY-shun THAYR-uh-pee)
A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote brachytherapy or remote brachytherapy.

high-energy photon therapy ( hy-EH-nur-jee FOH-ton THAYR-uh-pee)
A type of radiation therapy that uses high-energy photons (units of light energy). High-energy photons penetrate deeply into tissues to reach tumors while giving less radiation to superficial tissues such as the skin.

high-grade lymphoma
A type of lymphoma that grows and spreads quickly, and has severe symptoms. It is seen frequently in patients who are HIV-positive (AIDS-related lymphoma). Also called aggressive or intermediate-grade lymphoma.

high-grade squamous intraepithelial lesion
HSIL. A precancerous condition in which the cells of the uterine cervix are moderately or severely abnormal.

high-risk cancer
Cancer that is likely to recur (come back), or spread.

highly active antiretroviral therapy
HAART. Treatment for human immunodeficiency virus (HIV) infection that uses a combination of several antiretroviral drugs. The drugs inhibit the ability of the virus to multiply in the body, and they slow down the development of AIDS.

hilar
Refers to the area where nerves and blood vessels attach to an organ.

histamine dihydrochloride
A drug being studied for its ability to enhance the effectiveness of IL-2 in treating acute myeloid leukemia.

histiocytic lymphoma
An outdated term referring to non-Hodgkin's lymphomas made up of large abnormal lymphoid cells. Histiocytic lymphomas include mature B-cell and T-cell non-Hodgkin's lymphomas. Many tumors that were once called histiocytic lymphomas are now considered to be a type of large cell lymphoma.

histologic examination
The examination of tissue specimens under a microscope.

histology
The study of tissues and cells under a microscope.

histone
A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.

histone deacetylase
HDAC. An enzyme that changes the way histone binds to DNA. HDAC inhibitors are being studied as a treatment for cancer.

histone deacetylase inhibitor (HIS-tone dee-uh-SET-ih-lase in-HIH-bih-ter)
HDAC inhibitor. A substance that causes a chemical change that stops tumor cells from dividing. HDAC inhibitors are being studied in the treatment of cancer.

histopathology (HISS-toh-pa-THOL-oh-jee)
The study of diseased cells and tissue using a microscope.

historic cohort study
A research study in which the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) are compared for a particular outcome (such as lung cancer). Also called a retrospective cohort study.

historical control subject
An individual treated in the past and used in a comparison group when researchers analyze the results of a clinical study that had no control group. The use of a control, or comparison, group helps researchers determine the effects of a new treatment more accurately.

HIV
Human immunodeficiency virus, the cause of acquired immunodeficiency syndrome (AIDS).

HIV antibody
A substance produced by certain white blood cells in reaction to contact with HIV, the human immunodeficiency virus.

HIV positive
Infected with the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS).

HLA
Human lymphocyte antigen. One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign substances. These antigens vary from person to person, and an HLA test is done before organ transplantation to find out if tissues match between a donor and a recipient. Also called human leukocyte antigen.

HMG-CoA reductase inhibitor (HMG-koh-EN-zime-A ree-DUK-tayz in-HIH-bih-ter)
Hydroxymethylglutaryl-coenzyme A reductase inhibitor. A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. HMG-CoA reductase inhibitor drugs are called statins.

HNPCC
Hereditary nonpolyposis colon cancer. An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, often before the age of 50. Also called Lynch syndrome.

Hodgkin's disease (HOJ-kinz...)
A cancer of the immune system that is marked by the presence of a type of cell called the Reed Sternberg cell. Symptoms include the painless enlarged lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin's lymphoma.

Hodgkin's lymphoma (HOJ-kinz lim-FOH-muh)
A cancer of the immune system that is marked by the presence of a type of cell called the Reed Sternberg cell. Symptoms include the painless enlarged lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin's disease.

holmium Ho 166 DOTMP
A drug containing a radioactive isotope that is used in the diagnosis and treatment of cancer.

holy thistle
Cnicus benedictus. A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Holy thistle may have anti-inflammatory and anticancer effects. Also called blessed thistle, St. Benedict's thistle, cardin, and spotted thistle.

homeopathic medicine
An alternative approach to medicine based on the belief that natural substances, prepared in a special way and used most often in very small amounts, restore health. According to these beliefs, in order for a remedy to be effective, it must cause in a healthy person the same symptoms being treated in the patient. Also called homeopathy.

homeostasis (HOH-mee-oh-STAY-sis)
A state of balance among all the body systems needed for the body to survive and function correctly. In homeostasis, body levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins, and temperature are constantly adjusted to respond to changes inside and outside the body, to keep them at a normal level.

homeostatic (HOH-mee-oh-STA-tik)
Having to do with homeostasis, which is a state of balance among all the body systems, needed for the body to function correctly.

homoharringtonine
An anticancer drug that belongs to the plant alkaloid family of drugs.

hormonal therapy
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called hormone therapy, hormone treatment, or endocrine therapy.

hormone
A chemical made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in a laboratory.

hormone receptor
A protein on the surface of a cell that binds to a specific hormone. The hormone causes many changes to take place in the cell.

hormone receptor test
A test to measure the amount of certain proteins, called hormone receptors, in cancer tissue. Hormones can attach to these proteins. A high level of hormone receptors may mean that hormones help the cancer grow.

hormone replacement therapy
HRT. Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called menopausal hormone therapy.

hormone responsive
In oncology, describes cancer that responds to hormone treatment.

hormone therapy (HOR-mone THAYR-uh-pee)
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called hormonal therapy, hormone treatment, or endocrine therapy.

hormone treatment
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body's natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called hormonal therapy, hormone therapy, or endocrine therapy.

Horner's syndrome
A condition in which one side of the face is flushed, does not produce sweat, and has a constricted pupil and drooping eyelid. It can be caused by an injury to, or paralysis of, nerves in the neck, or by a tumor.

hospice (HOS-pis)
A program that provides special care for people who are near the end of life and for their families, either at home, in freestanding facilities, or within hospitals.

host cell
A cell that is infected by a virus or another type of microorganism.

hot flash
A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).

hot nodule
When radioactive material is used to examine the thyroid with a scanner, nodules that collect more radioactive material than the surrounding thyroid tissue are considered "hot." Hot nodules are rarely malignant. Hot nodules are sometimes called hyperfunctioning nodules.

hotspot
In genetics, an area of DNA that is likely to mutate (change).

HPPH
2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a. A drug that is used in photodynamic therapy that is absorbed by tumor cells; when exposed to light, it becomes active and kills the cancer cells.

HPV
Human papillomavirus. A member of a family of viruses that can cause abnormal tissue growth (for example, genital warts) and other changes to cells. Infection with certain types of HPV increases the risk of developing cervical cancer.

HPV vaccine (... vak-SEEN)
Human papillomavirus vaccine. A vaccine that is being studied in the prevention of human papillomavirus infection and cervical cancer. Infection with certain types of HPV increases the risk of developing cervical cancer.

HRT
Hormone replacement therapy. Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called menopausal hormone therapy.

HSIL
High-grade squamous intraepithelial lesion. A precancerous condition in which the cells of the uterine cervix are moderately or severely abnormal.

HTLV-1
Human T-cell leukemia virus type 1. A retrovirus that infects T-cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles used to inject drugs, through sexual contact, and from mother to child at birth or through breast-feeding.

hu14.18-interleukin-2 fusion protein
An anticancer drug in which hu14.18, a monoclonal antibody, is combined with interleukin-2. The monoclonal antibody binds to the cancer cells and delivers IL-2, which stimulates the immune system to destroy the cancer cells.

Hu3S193
A monoclonal antibody that is being studied in the treatment of some types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to cancer cells. Hu3S193 binds to the protein Lewis(y), which is found on colon, breast, lung, ovary, and prostate cancer cells.

Huang Lian
A Chinese herb that has been used as a treatment for a variety of medical problems. It is being studied as an anticancer drug.

HuHMFG1
A monoclonal antibody that binds to the protein MUC1, which is found on breast, ovarian, pancreatic, gastric, and colon cancer cells. Monoclonal antibodies are laboratory-produced substances that can locate and bind to cancer cells. HuHMFG1 is being studied in the treatment of some types of cancer.

human corticotropin-releasing factor
hCRF. A substance that is being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. hCRF may help reduce symptoms caused by edema (swelling) of the brain. It belongs to the family of drugs called neurohormones.

human epidermal growth factor receptor 2
HER2/neu. The HER2/neu protein is involved in growth of some cancer cells. Also called c-erbB-2.

human herpesvirus 8
HHV8. A type of herpesvirus that may cause Kaposi's sarcoma (a rare cancer that can cause skin lesions) and a type of lymphoma (cancer that begins in the lymph system), especially in patients who have a weak immune system. Also called Kaposi's sarcoma-associated herpesvirus (KSHV).

human immunodeficiency virus
HIV. The cause of acquired immunodeficiency syndrome (AIDS).

human leukocyte antigen
HLA. One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign substances. These antigens vary from person to person, and an HLA test is done before organ transplantation to find out if tissues match between a donor and a recipient. Also called human lymphocyte antigen.

human lymphocyte antigen
HLA. One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign substances. These antigens vary from person to person, and an HLA test is done before organ transplantation to find out if tissues match between a donor and a recipient. Also called human leukocyte antigen.

human papillomavirus (HYOO-mun PA-pih-LOH-muh-VY-rus)
HPV. A member of a family of viruses that can cause abnormal tissue growth (for example, genital warts) and other changes to cells. Infection with certain types of HPV increases the risk of developing cervical cancer.

human papillomavirus vaccine (HYOO-mun PA-pih-LOH-muh-VY-rus vak-SEEN)
HPV vaccine. A vaccine that is being studied in the prevention of human papillomavirus infection and cervical cancer. Infection with certain types of HPV increases the risk of developing cervical cancer.

human T-cell leukemia virus type 1
A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles used to inject drugs, through blood transfusions, through sexual contact, and from mother to child at birth or through breast-feeding.

humidifier (hyoo-MID-ih-fye-er)
A machine that puts moisture in the air.

Hurthle cell neoplasm (HEERT-leh...NEE-oh-PLA-zum)
An uncommon type of thyroid tumor that can be benign or malignant.

Hycamtin (hy-KAM-tin)
A drug used to treat some types of cancer. It belongs to the family of drugs called topoisomerase inhibitors. Also called topotecan.

hydatidiform mole (hy-da-TID-ih-form mohl)
A condition in women of childbearing age in which grape-like cysts grow in the uterus after conception (fertilization of an egg by a sperm). Hydatidiform moles may change into a type of cancer called choriocarcinoma or gestational trophoblastic tumor. Also called molar pregnancy.

hydration
Combining with water.

hydrazine sulfate
A substance that has been studied as a treatment for cancer and as a treatment for cachexia (body wasting) associated with advanced cancer.

hydrocephalus (hye-dro-SEF-uh-lus)
The abnormal buildup of cerebrospinal fluid in the ventricles of the brain.

hydrocortisone
A drug used to relieve the symptoms of certain hormone shortages and to suppress an immune response.

hydrogen peroxide
A chemical used in bleaches, dyes, cleansers, antiseptics, and disinfectants. In a concentrated form, it is toxic and irritating to tissues.

hydrolysis
A chemical reaction that uses water to break down a compound.

hydromorphone
A drug used to relieve pain.

hydronephrosis
Abnormal enlargement of a kidney, which may be caused by blockage of the ureter (such as by a kidney stone) or chronic kidney disease that prevents urine from draining into the bladder.

hydroureter
Abnormal enlargement of the ureter caused by any blockage that prevents urine from draining into the bladder.

hydroxychloroquine
A substance that decreases immune responses in the body. It is used to treat some autoimmune diseases, and is being studied as a treatment for graft-versus-host disease. Hydroxychloroquine belongs to the family of drugs called antiprotozoals.

hydroxymethylglutaryl-coenzyme A reductase inhibitor (hy-DROK-see-MEH-thul-GLOO-tuh-ril koh-EN-zime-A ree-DUK-tayz in-HIH-bih-ter)
HMG-CoA reductase inhibitor. A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. HMG-CoA reductase inhibitor drugs are called statins.

hydroxyurea
An anticancer drug that belongs to the family of drugs called antimetabolites.

hygiene (HY-jeen)
The science of health, and the practice of cleanliness that promotes good health and well-being.

hyperactivity (HY-per-AK-TIH-vih-tee)
A higher than normal level of activity. Hyperactivity can be used to describe the increased action of a body function, such as hormone production, or behavior. A person who is hyperactive may seem to be always moving or fidgeting, impulsive, unable to concentrate, and talking too much.

hyperalimentation
A form of nutrition that is delivered into a vein. Hyperalimentation does not use the digestive system. It may be given to people who are unable to absorb nutrients through the intestinal tract because of vomiting that won't stop, severe diarrhea, or intestinal disease. It may also be given to those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible to give all of the protein, calories, vitamins and minerals a person needs using parenteral nutrition. Also known as parenteral or total parenteral nutrition (TPN).

hyperbaric oxygen
Oxygen that is at an atmospheric pressure higher than the pressure at sea level. Breathing hyperbaric oxygen to enhance the effectiveness of radiation therapy is being studied.

hypercalcemia (hye-per-kal-SEE-mee-a)
Abnormally high blood calcium.

hyperfractionated radiation therapy
A way of giving radiation therapy in smaller-than-usual doses two or three times a day instead of once a day. Also called hyperfractionation and superfractionated radiation therapy.

hyperfractionation (hy-per-FRAK-shun-AY-shun)
A way of giving radiation therapy in smaller-than-usual doses two or three times a day instead of once a day. Also called hyperfractionated radiation therapy and superfractionated radiation therapy.

hyperglycemia
Abnormally high blood sugar.