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Absolute Contraindication
(En español)
When a particular treatment or procedure should not be used under any circumstance because of the severe and potentially life-threatening risks involved.
See Related Term(s): Contraindication
A skin disorder characterized by velvety, light brown-to-black markings that develop mainly in the folds of the body, such as in the armpits, groin, and creases of the neck. Acanthosis nigricans can be an inherited condition or can occur as the result of an endocrine disorder, cancer, or use of certain medications.
Acquired Immunodeficiency Syndrome (AIDS) (En español)
A disease of the immune system due to infection with HIV. HIV destroys the CD4 T lymphocytes (CD4 cells) of the immune system, leaving the body vulnerable to life-threatening infections and cancers. Acquired immunodeficiency syndrome (AIDS) is the most advanced stage of HIV infection.
See Related Term(s): AIDS Case Definition, HIV Progression, Human Immunodeficiency Virus
Immunity that develops after exposure to a disease-causing infectious microorganism or other foreign substance, such as following infection or vaccination.
See Related Term(s): Acquired Immunity, Passive Immunity
Also known as: Primary HIV Infection
Early stage of HIV infection that extends approximately 2 to 4 weeks from initial infection until the body produces enough HIV antibodies to be detected by an HIV antibody test. Because the virus is replicating rapidly, HIV is highly infectious during this stage of infection.
See Related Term(s): Acute Retroviral Syndrome, HIV Progression
Acute Infection and Early Diseases Research Program (AIEDRP) (En español)
A federally funded research program that studies how HIV infects humans and how the disease progresses to AIDS.
Acute Retroviral Syndrome (En español)
Flu-like symptoms of acute HIV infection that may appear approximately 2 to 4 weeks after infection. Symptoms such as fever, headache, fatigue, and swollen lymph nodes can last from a few days to 4 weeks, and then subside. During the acute stage of HIV infection, many, but not all, people will have symptoms of acute retroviral syndrome.
See Related Term(s): Acute HIV Infection
Any disease involving swollen glands, especially the lymph nodes.
See Related Term(s): Lymph Nodes
A group of viruses that use DNA as their genetic material and commonly cause respiratory and eye infections. People with weakened immune systems, including people with HIV, have a greater risk for serious complications from an adenovirus infection than people with healthy immune systems.
See Related Term(s): Virus
Taking medications exactly as prescribed. Poor adherence to an HIV treatment regimen increases the risk for developing drug-resistant HIV and virologic failure.
See Related Term(s): Drug Resistance, Virologic Failure
A substance added to a drug to enhance the effects of the drug. Adjuvant also refers to a substance added to a vaccine to boost the body’s immune response to the vaccine.
Adverse Drug Reaction (ADR) (En español)
Any unintended, undesirable response to a drug taken at a normal dose for normal use. Adverse drug reactions (ADRs) are classified by onset, severity, and type.
Any undesirable experience associated with the use of a drug or other medical product.
See Related Term(s): Adverse Drug Reaction
Total or near-total absence of gamma globulins in the blood. Gamma globulins are a class of blood proteins that include most antibodies. Agammaglobulinemia may be due to certain genetic diseases or to acquired diseases such as HIV/AIDS.
See Related Term(s): Gamma Globulin
Agency for Healthcare Research and Quality (AHRQ) (En español)
A federally funded agency that supports research to improve the quality, safety, efficiency, and effectiveness of health care in the United States.
AIDS Clinical Trials Group (ACTG) (En español)
Formerly called Adult AIDS Clinical Trials Group (AACTG). Federally funded program that supports the largest network of HIV/AIDS researchers and clinical trial units in the world. AIDS Clinical Trials Group (ACTG) develops and conducts research related to HIV infection and its complications.
AIDS Drug Assistance Programs (ADAPs) (En español)
Federally funded programs that provide medications and other HIV-related services to low-income, uninsured, and underinsured people with HIV/AIDS. Services of AIDS Drug Assistance Programs (ADAPs) are available in all 50 states and U.S. territories.
AIDS Education and Training Centers (AETCs) (En español)
Regional centers that conduct education and training programs for health care providers who treat people living with HIV/AIDS. Training is targeted to providers who serve minority populations, the homeless, rural communities, prisoners, community and migrant health centers, and Ryan White HIV/AIDS Program-funded sites. AIDS Education and Training Centers (AETCs) serve all 50 states and many U.S. territories.
AIDS Service Organization (ASO) (En español)
A non-governmental organization that provides services related to the prevention and treatment of HIV/AIDS.
A type of cancer that when diagnosed in a person with HIV marks the development of AIDS. AIDS-defining cancers include Kaposi sarcoma, non-Hodgkin lymphoma, and invasive cervical cancer.
See Related Term(s): Acquired Immunodeficiency Syndrome
A type of cancer that is more likely to occur in people with HIV/AIDS than in people with healthy immune systems. AIDS-related cancers include lung cancer, anal cancer, and Hodgkin lymphoma.
See Related Term(s): Acquired Immunodeficiency Syndrome
AIDS-Related Complex (ARC) (En español)
Symptoms that signal the transition from asymptomatic HIV infection to symptomatic HIV infection (but not full-blown AIDS). Symptoms can include recurring fever, unexplained weight loss, swollen lymph glands, diarrhea, or fungal infection of the mouth.
See Related Term(s): Acquired Immunodeficiency Syndrome, Human Immunodeficiency Virus
The federal source for HIV/AIDS medical practice guidelines, clinical trials, and other research information for health care providers, researchers, people affected by HIV/AIDS, and the general public. Information is available via the Web, phone, e-mail, and postal mail.
See Related Term(s): infoSIDA
A protein made by the liver and found in high concentrations in blood. This protein may be measured as part of a liver function test.
See Related Term(s): Liver Function Test
Alkaline Phosphatase (ALP) (En español)
An enzyme found throughout the body, especially in the liver and bone. Alkaline phosphatase may be measured as part of a liver function test.
See Related Term(s): Liver Function Test
Loss of hair. Alopecia may be an adverse effect of some antiretroviral (ARV) drugs.
The chemical building blocks of proteins.
See Related Term(s): Peptide, Protein
A blood disorder caused by reduced number or function of red blood cells. Symptoms may include shortness of breath, fatigue, and rapid heartbeat. HIV-associated causes of anemia include progression of HIV disease, opportunistic infections, and certain antiretroviral (ARV) drugs.
See Related Term(s): Red Blood Cell
Lack or loss of appetite. Anorexia is also commonly used to refer to anorexia nervosa, which is an eating disorder.
The time period before childbirth. Antepartum refers to the mother.
A drug used to kill or suppress the growth of microorganisms, such as bacteria and fungi.
See Related Term(s): Microorganism
Also known as: Blood Thinner
A drug used to prevent the blood from clotting.
A drug used to kill or suppress the growth of fungi.
See Related Term(s): Fungus
Any substance that is foreign to the body and triggers an immune response. Antigens include bacteria, viruses, and allergens, such as pollen.
See Related Term(s): Immune Response
Antigen-Presenting Cell (APC) (En español)
A type of immune cell that enables a T lymphocyte (T cell) to recognize an antigen and mount an immune response against the antigen. Antigen-presenting cells (APCs) include macrophages, dendritic cells, and B lymphocytes (B cells).
See Related Term(s): Antigen, Immune Response, T Lymphocyte
A drug used to inhibit the growth or spread of tumors or cancer cells.
A drug used to kill or suppress the growth of protozoans.
See Related Term(s): Protozoan
A drug used to prevent a retrovirus, such as HIV, from replicating. The term primarily refers to antiretroviral (ARV) HIV drugs.
See Related Term(s): Drug Class, Retrovirus
Antiretroviral Pregnancy Registry (En español)
A project established to monitor prenatal exposures to antiretroviral (ARV) drugs and to detect any potential increase in the risk of related birth defects. Pregnant women exposed to ARV drugs voluntarily enroll in the Registry through their health care providers. Information provided to the Registry includes no identifying patient information.
Antiretroviral Toxic Neuropathy (En español)
Nerve damage that is due to antiretroviral (ARV) drugs.
See Related Term(s): Neuropathy
A drug made of short segments of DNA or RNA that can bind to and alter or suppress the function of viral DNA or RNA. Antisense antivirals prevent viruses from replicating.
A drug used to prevent the growth or replication of viruses.
See Related Term(s): Virus
Also known as: Canker Sore
An open sore that develops on parts of the mouth (inner surface of the cheeks and lips, tongue, soft palate, or base of the gums). Although aphthous ulcers are non-contagious and non-life-threatening, they can be very painful. Aphthous ulcers are more common and more likely to reoccur in people with HIV than in people without HIV.
Also known as: Programmed Cell Death
The deliberate, programmed death of a cell. Apoptosis is a normal biological process that helps the body stay healthy by eliminating old or damaged cells. One of the ways that HIV infection gradually destroys the immune system is by causing apoptosis of CD4 T lymphocytes (CD4 cells).
See Related Term(s): CD4 T Lymphocyte
A drug approved by the Food and Drug Administration (FDA) for sale in the United States. The extensive FDA drug approval process includes many steps, including laboratory and animal studies, clinical trials for safety and efficacy, filing of a New Drug Application by the drug manufacturer, FDA review of the application, and FDA approval or rejection of the application.
See Related Term(s): Clinical Trial, Food and Drug Administration, New Drug Application
Area Under the Curve (AUC) (En español)
A measure of how much drug reaches a person's bloodstream in a given period of time after a dose is given. The information is useful for determining dosing and for identifying potential drug interactions.
See Related Term(s): Drug Interaction
Any of the treatment groups in a clinical trial.
See Related Term(s): Clinical Trial
Any irregularity in rhythm or rate of the heartbeat.
Joint pain with additional symptoms such as redness, tenderness to touch, loss of motion, or swelling. Arthralgia is a common symptom of HIV infection and may be caused by drugs used to treat HIV and opportunistic infections.
An infection caused by the fungus
Aspergillus. Invasive aspergillosis is a serious lung infection that can spread to other parts of the body. It occurs almost exclusively in people with low blood levels of neutrophils, a type of white blood cell, and weakened immune systems. Invasive aspergillosis in a person with HIV is rare.
See Related Term(s): Opportunistic Infection
Weakness; lack or loss of energy or strength.
Asymptomatic HIV Infection (En español)
Also known as: Clinical Latency
Stage of HIV infection during which there are no symptoms of HIV infection. During this stage of HIV infection, which varies in length of time from person to person, HIV slowly destroys the immune system. Antiretroviral therapy (ART) can prevent the onset of symptomatic HIV infection and AIDS.
See Related Term(s): HIV Progression
Impaired coordination of voluntary muscle movements. Ataxia may be an adverse effect of drugs used to treat either HIV or opportunistic infections or may be caused by neurological conditions associated with HIV.
The gradual build-up of plaque inside of artery walls. (Plaque is made up of fat, cholesterol, calcium, and other substances found in blood.) Over time, the plaque hardens and narrows the arteries, decreasing the flow of oxygen-rich blood to organs and other parts of the body.
A condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue. Autoimmune disorders may be caused by drugs used to treat opportunistic infections.
See Related Term(s): Immune System
Avascular Necrosis (AVN) (En español)
Death of bone tissue (osteonecrosis) due to a lack of blood supply. Avascular necrosis (AVN) most commonly affects the hip. Symptoms include pain in the affected area of the body, limited range of motion, joint stiffness, muscle spasms, and limping. AVN is associated with several medical conditions, including cancer and HIV infection.
See Related Term(s): Osteonecrosis