Glossary of HIV/AIDS Terms

Reviewed by: HU Medical Review Board | Last reviewed: November 2019

Receiving an HIV diagnosis and starting treatment can be very overwhelming at times. Understanding medical terminology and other commonly used terms can be helpful for anyone living with HIV. Some of the most frequently used terms and their definitions are below. This is not an exhaustive list of all important HIV-related terms, but it is a good place to start for anyone seeking basic information.


ADA (Americans with Disabilities Act)

A federal law which bans discrimination against people with physical or mental disabilities at work, school, transportation, or any other public place.

ADAP program

The AIDS Drug Assistance Program helps low-income people get the HIV-drugs they need.


Acquired immunodeficiency syndrome. This is the disease you get if HIV is not controlled with treatment.


Antiretroviral drugs that stop HIV from maturing and multiplying. Also called antiretroviral therapy (ART).


CD4 count

A test that measures the number of T-cells in the body. A normal range is 500 to 1,500. If the CD4 count drops below 200, then person is diagnosed with AIDS.


Living with more than one infection. HIV and hepatitis C are common co-infections.

Complete blood count

A type of blood test to measure the amount and health of red blood cells, white blood cells and platelets.

Concordant couple

When both people in a relationship are HIV positive.



The process of telling someone you are living with HIV.

Discordant couple

When one person in a relationship is HIV positive and the other is HIV negative. Also called a mixed-status couple.


The act of treating someone with disrespect or differently based on how they look or because you don’t like something about them.


The specific amount of medication you should take and how often.

Drug resistance

What happens when a virus or bacteria changes that the medication used to treat it stops working or works less well than before.


False negative

A test result that shows a person does not have a disease when they really do.

False positive

A test result that shows a person has a disease when they do not.



A disease that stops blood from clotting correctly.

HIV life cycle

The 7 steps that HIV follows to mature and multiply in the body.



Men who have sex with men.

Mixed status couple

When one person in a relationship is HIV positive and the other is HIV negative. Also called a discordant couple.



Post-exposure prophylaxis. A course a treatment taken after being exposed to HIV during a transmission event.


Pre-exposure prophylaxis. A prevention method (usually in the form of medication) you take to reduce the risk of getting HIV.


Sex worker

A person who has sex for housing, food, money or other goods.


Sexually transmitted disease. Also known as sexually transmitted infection (STI).


Sexually transmitted infection. Also known as sexually transmitted disease (STD).


Judging someone in a negative way because of their race, gender, culture, or health condition.


Treatment adherence

Following all recommendations to maintain your health, including taking all of your drugs exactly as your doctor prescribes.



Undetectable equals untransmittable. An undetectable viral load means a person with HIV cannot transmit the virus.


When the amount of HIV (viral load) in the blood is so low it cannot be found in blood tests.


Viral load

The amount of HIV in the blood.


Window period

The time between when a person has been infected with HIV and when tests can detect the virus.

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