arthritisA disease that causes inflammation and pain in the joints.
artificial pacemaker(AR-tih-FIH-shul PAYS-may-ker) An electronic device that is implanted in the body to monitor heart rate and rhythm.
arzoxifene hydrochloride(ar-ZOX-ih-feen HY-droh-KLOR-ide) A substance being studied in the treatment of osteoporosis and breast cancer.
asbestosA toxic material that was once used in housing insulation and fireproofing. Because some forms of asbestos have been linked to certain lung diseases, it…
asbestosis(as-bes-TOH-sis) A lung disease caused by breathing in particles of asbestos (a group of minerals that take the form of tiny fibers).
ascites(uh-SY-teez) Abnormal buildup of fluid in the abdomen that may cause swelling. In late-stage cancer, tumor cells may be found in the fluid in the abdomen.
ascorbic acid(uh-SKOR-bik A-sid) One of several vitamins that the body needs in small amounts to function and stay healthy.
asparaginase(as-PA-ruh-jih-nayz) A drug that is used to treat acute lymphoblastic leukemia (ALL) and is being studied in the treatment of some other types of cancer.
aspartate transaminaseAn enzyme found in the liver, heart, and other tissues. A high level of aspartate transaminase released into the blood may be a sign of liver or heart…
aspergillosisAn infectious fungal disease that occurs most often in the skin, ears, nasal sinuses, and lungs of people with suppressed immune systems.
Aspergillus(A-sper-JIH-lus) Fungi commonly found in soil. Certain types of Aspergillus may cause disease, especially in people who have suppressed immune systems.
aspirate(AS-pi-rit) Fluid withdrawn from a lump (often a cyst) or a nipple.
Aspiration(as-per-AY-shun) Removal of fluid or tissue through a needle. Also, the accidental breathing in of food or fluid into the lungs.
aspirinA drug that reduces pain, fever, inflammation, and blood clotting. Aspirin belongs to the family of drugs called nonsteroidal anti-inflammatory agents.
assay(AS-say) A laboratory test to find and measure the amount of a specific substance.
AssessmentCharges levied against a property for tax purposes or to pay for municipal or association improvements such as curbs, sewers, or grounds maintenance.
AssignmentAssignment occurs when someone who has written, or sold, a listed option receives a notice that the option has been exercised and he or she must fulfill…
asthma(AZ-muh) A chronic disease in which the bronchial airways in the lungs become narrowed and swollen, making it difficult to breathe.
Astrocyte(AS-troh-site) A star-shaped cell that helps nerve cells in the brain and spinal cord work the way they should. An astrocyte is a type of glial cell.
astrocytoma(AS-troh-sy-TOH-muh) A tumor that begins in the brain or spinal cord in small, star-shaped cells called astrocytes.
asymmetryLack or absence of balanced proportions between parts of a thing.
asymptomaticHaving no signs or symptoms of disease.
AT/RTAn aggressive cancer of the central nervous system, kidney, or liver that occurs in very young children.
AT7519MA substance being studied in the treatment of some types of cancer. AT7519M blocks enzymes needed for cells to divide.
AT9283A substance being studied in the treatment of some types of cancer. It blocks enzymes (Aurora kinases) involved in cell division and may kill cancer cells.
atamestaneA substance that is being studied in the treatment of cancer. Atamestane blocks the production of the hormone estrogen in the body.
ataxia-telangiectasiaA rare, inherited, progressive, degenerative disease of childhood that causes loss of muscle control, a weakened immune system, and an increased risk of…
atelectasis(at-uh-LEK-tuh-sis) Failure of the lung to expand (inflate) completely. This may be caused by a blocked airway, a tumor, general anesthesia, pneumonia or…
AtherosclerosisA chronic disease in which excessive amounts of fat and cholesterol remaining in the bloodstream collect on the inside walls of arteries, forming plaque…
athymic nude mouseA type of laboratory mouse that is hairless, lacks a normal thymus gland, and has a defective immune system because of a genetic mutation.
atiprimod(uh-TIH-prih-mod) A substance being studied in the treatment of certain multiple myelomas and other advanced cancers.
ATLLAn aggressive (fast-growing) type of T-cell non-Hodgkin lymphoma caused by the human T-cell leukemia virus type 1 (HTLV-1).
ATN-161A substance being studied in the treatment of some types of cancer. ATN-161 may prevent the spread of tumor cells and the growth of new blood vessels from…
atorvastatin(uh-TOR-vuh-STA-tin) The active ingredient in a drug used to lower the amount of cholesterol in the blood and to prevent stroke, heart attack, and angina…
atorvastatin calcium(uh-TOR-vuh-STA-tin KAL-see-um) A drug used to lower the amount of cholesterol in the blood and to prevent stroke, heart attack, and angina (chest pain).
AtovaquoneA drug used against malaria. It is found in the combination atovaquone-proguanil which can be used for both prevention and treatment.
ATPA substance present in all living cells that provides energy for many metabolic processes and is involved in making RNA.
ATRAA form of vitamin A that is made by the body, and can also be made in the laboratory.
atrasentanA substance that is being studied in the treatment of cancer. It belongs to the family of drugs called endothelin-1 protein receptor antagonists.
ATT/RHTAn aggressive cancer of the central nervous system, kidney, or liver that occurs in very young children.
attenuatedWeakened or thinned. Attenuated strains of disease-causing bacteria and viruses are often used as vaccines.
Attest/AttestationWhen you apply for health coverage through the Marketplace, you're required to agree (or "attest") to the truth of the information provided by signing the…
Atypical(a-tip'ih-kul) irregular; not conformable to the type; an unusual type.
atypical hyperplasia(AY-TIP-ih-kul HY-per-PLAY-zhuh) A benign (noncancerous) condition in which cells look abnormal under a microscope and are increased in number.
atypical teratoid/rhabdoid tumor(AY-TIH-pih-kul TER-uh-toyd/RAB-doyd TOO-mer) An aggressive cancer of the central nervous system, kidney, or liver that occurs in very young children.
Augmentin(awg-MEN-tin) A drug used to treat bacterial infections. Adding the chemical clavulanate potassium to the antibiotic amoxicillin increases the amount of…
augmerosen(awg-MER-oh-sen) A substance being studied in the treatment of cancer. It may kill cancer cells by blocking the production of a protein that makes cancer…
auricular(aw-RIK-yoo-ler) Having to do with the ear.
Aurimmune(AW-rih-MYOON) A substance being studied in the treatment of some types of cancer.
Aurora kinase inhibitor AT9283(uh-ROR-uh KY-nayz in-HIH-bih-ter...) A substance being studied in the treatment of some types of cancer.
Authorized RepresentativeSomeone who you choose to act on your behalf with the Marketplace, like a family member or other trusted person.
AutochthonousRegarding malaria, it refers to local transmission by mosquitoes. This can either be indigenous (a geographic area where malaria occurs regularly) or…
autoclave(AW-toh-KLAYV) A device that uses steam under high pressure to sterilize medical and laboratory supplies and equipment.
autoclave-resistant factorA substance found in soybeans that may slow down or stop the spread of cancer. This substance does not break down in an autoclave (a device that uses…
Autoimmune disease(AW-toh-ih-MYOON...) A condition in which the body recognizes its own tissues as foreign and directs an immune response against them.
autoimmune enteropathy(AW-toh-ih-MYOON en-teh-RAH-puh-thee) A rare disease in which certain cells in the intestine are destroyed by a patient's immune system.
autoimmune hemolytic anemia(AW-toh-ih-MYOON hee-moh-LIH-tik uh-NEE-mee-uh) A condition in which the body's immune system stops red blood cells from forming or causes them to clump…
Autoimmune processA process where the body’s immune system attacks and destroys body tissue that it mistakes for foreign matter.
Autologous(aw-TAH-luh-gus) Taken from an individual's own tissues, cells, or DNA.
autologous bone marrow(aw-TAH-luh-gus bone MAYR-oh) In transplantation, refers to a person's own bone marrow.
autologous bone marrow transplantation(aw-TAH-luh-gus bone MAYR-oh tranz-plan-TAY-shun) A procedure in which bone marrow is removed from a person, stored, and then given back to the person…
autologous lymphocyte(aw-TAH-luh-gus LIM-foh-site) In transplantation, refers to a person's own white blood cells.
autologous stem cell transplantation(aw-TAH-luh-gus ... tranz-plan-TAY-shun) A procedure in which blood-forming stem cells (cells from which all blood cells develop) are removed, stored, and…
autologous tumor cell(aw-TAH-luh-gus TOO-mer sel) A cancer cell from an individual's own tumor.
Autonomic Nervous System(AW-toh-NAH-mik NER-vus SIS-tem) The part of the nervous system that controls muscles of internal organs (such as the heart, blood vessels, lungs…
Autonomic NeuropathyThe autonomic nervous system (comprised of the sympathetic and parasympathetic nervous systems) are the nerves which control a whole range of bodily…
autophagy(aw-TOF-uh-jee) A normal process in which a cell destroys proteins and other substances in its cytoplasm (the fluid inside the cell membrane but outside…
Avage(AY-vahj) A drug used on the skin to treat several skin conditions. It is also being studied in the treatment of basal cell skin cancer and basal cell…
Avandia(uh-VAN-dee-uh) A drug that helps control the amount of glucose (sugar) in the blood and is being studied in the prevention and treatment of some types of…
Avastin(uh-VAS-tin) A monoclonal antibody used in the treatment of colorectal cancer that has spread.
Avelox(A-veh-lox) A drug used to treat bacterial infections. It is a type of fluoroquinolone. Also called moxifloxacin and moxifloxacin hydrochloride .
AvitaA topical preparation of tretinoin that is used to treat acne. Tretinoin is a form of vitamin A.
AvodartA drug used to treat symptoms of an enlarged prostate gland. It is being studied in the treatment of male hair loss and prostate cancer.
avoidance(uh-VOY-dunts) The act of staying away from people, places, and thoughts that may cause anxiety, pain, or unpleasant feelings.
axillary(AK-sih-LAYR-ee) Pertaining to the armpit area, including the lymph nodes that are located there.
axillary dissection(AK-sih-LAYR-ee dy-SEK-shun) Surgery to remove lymph nodes found in the armpit region. Also called axillary lymph node dissection.
axillary lymph node(AK-sih-LAYR-ee limf ...) A lymph node in the armpit region that drains lymph channels from the breast.
axillary lymph node dissection(AK-sih-LAYR-ee limfâ¦dy-SEK-shun) Surgery to remove lymph nodes found in the armpit region. Also called axillary dissection.
axitinib(AX-ih-TIH-nib) A substance being studied in the treatment of some types of cancer.
azacitidine(ay-zuh-SITE-ih-deen) A drug that is used to treat myelodysplastic syndromes and is being studied in the treatment of other types of cancer.
azaspirane(AY-zuh-SPEER-ane) A substance being studied in the treatment of certain multiple myelomas and other advanced cancers.
AZD0530A substance being studied in the treatment of some types of cancer. AZD0530 blocks enzymes needed for cancer growth.
AZD2171A substance being studied in the treatment of some types of cancer. AZD2171 blocks the growth of new blood vessels needed for tumors to grow and may kill…
AZD2281A substance being studied in the treatment of some types of cancer. It blocks enzymes that repair DNA damage caused by cancer treatments such as radiation…
AZD6244A substance being studied in the treatment of several types of cancer. AZD6244 blocks proteins needed for cell growth and may kill cancer cells.
azoxymethaneA substance that is used in cancer research to cause colon tumors in laboratory animals.
AZQAn anticancer drug that is able to cross the blood-brain barrier and kill cancer cells in the central nervous system. Also called diaziquone.
AZTA drug that inhibits the human immunodeficiency virus (HIV) that causes AIDS. Also called zidovudine.
B cellA white blood cell that comes from bone marrow. As part of the immune system, B cells make antibodies and help fight infections. Also called B lymphocyte.
B lymphocyteA white blood cell that comes from bone marrow. As part of the immune system, B lymphocytes make antibodies and help fight infections. Also called B cell.