Version July 2025
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What is an HIV blood test? —
This test checks for HIV in the blood.
HIV is a virus that can affect the body's "immune system." This is the body's infection-fighting system. People with HIV can get sick more easily than people without HIV. That's because their immune system cannot work as well to fight off infections or cancer.
There are 3 kinds of HIV blood tests:
●Combined antigen and antibody tests – These check the blood for HIV "antigens" and "antibodies." "Antigens" are substances (like parts of a virus) the immune system reacts to. "Antibodies" are proteins the body makes when a person has an infection.
●Antibody tests – These check the blood for antibodies only.
●Nucleic acid tests – These check for the genetic material inside the HIV virus.
Most of the time, these tests are done by taking a sample of blood and sending it to a lab. Sometimes, doctors do a "rapid" test. For this, they can do a fingerstick, rather than taking blood from a vein. A rapid test can give results in less than 20 minutes. If your rapid test is positive, your doctor or nurse will likely also do a blood test to confirm the results.
Why might I get an HIV blood test? —
Your doctor might order this test:
●If you have symptoms of HIV
●If you know or think you were exposed to HIV
●If you are at increased risk of getting HIV – Doctors recommend people who are more likely to get HIV get tested more often. Your level of risk depends on a few different things. These include your sex partners and whether you share needles for using drugs. Some people at high risk for HIV take medicines called "pre-exposure prophylaxis," or "PrEP." People who take PrEP still need to get tested for HIV often.
●If you have certain other conditions – If you were diagnosed with a new health problem, your doctor might order an HIV test. This is because people are more likely to get HIV at the same time as certain other infections, such as hepatitis B or hepatitis C.
●As part of routine screening – "Screening" means testing a person who does not have any symptoms. Doctors recommend everyone under 65 get tested for HIV once in their lifetime. Many people choose to get tested for HIV while they are getting tested for other sexually transmitted infections, or "STIs." It is also important to test for HIV during pregnancy. This is because a person with HIV can pass the infection to their baby.
How do I prepare for an HIV blood test? —
If you need to get a "blood draw," your doctor or nurse will tell you where to go for this.
It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.
What happens during a blood draw? —
A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.
Tell the person who takes your blood:
●If you take "blood thinner" medicines or have a bleeding problem – They will make sure your bleeding is under control before you leave.
●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.
●If you have a preferred arm to use
Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.
What do my results mean? —
Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.
●If your HIV test is positive, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out for sure if you have HIV.
It is possible for your first test to be positive and your second to be negative. If this happens, your doctor will do more tests to figure out whether you have HIV.
●If your HIV test is negative, you probably do not have HIV. But sometimes, the test can be negative in a person who only recently became infected. If your doctor thinks this is a possibility, they will do more tests.
If you have HIV:
●Your doctor will work with you to come up with a treatment plan. It is important to start treatment right away to help keep you healthy.
●They can also help you:
•Make a plan to tell your sex partners
•Learn how to prevent spreading HIV to other people
•Find local support groups or a counselor
If you do not have HIV, your doctor or nurse can talk to you about ways to protect yourself.
Patient education: HIV and AIDS (The Basics)
Patient education: Taking medicines to prevent HIV before exposure (The Basics)
Patient education: Exposure to HIV or hepatitis through blood or body fluids (The Basics)
Patient education: Preventing HIV after a possible exposure (The Basics)
Patient education: Starting treatment for HIV (The Basics)
Patient education: Tests to monitor HIV (The Basics)
Patient education: Vaccines for adults with HIV (The Basics)
Patient education: Testing for HIV (Beyond the Basics)
Patient education: Symptoms of HIV (Beyond the Basics)
Patient education: Initial treatment of HIV (Beyond the Basics)
Patient education: Tips for taking HIV medications by mouth (Beyond the Basics)
Patient education: HIV and pregnancy (Beyond the Basics)
