Depending on the test type, a person may have to wait up to 90 days after exposure for HIV to show up on test results. However, some tests can detect HIV after only 18 days.

Having sexual intercourse or sharing needles with someone with HIV can expose people to the virus.

Some experts recommend that people between 13 and 75 years old receive an HIV test at least once in their lives. However, some individuals — such as sex workers, males who have sex with males, and people who inject drugs — may want to consider getting tested for HIV more often, as they may be more likely to contract HIV.

Individuals whose sexual partners have HIV or may have it and people with HIV symptoms might also want to consider getting tested frequently.

This article examines the testing window for HIV, what the tests involve, and more.

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According to the Centers for Disease Control and Prevention (CDC), all HIV tests have an HIV testing window.

A testing window refers to the amount of time a person must wait after possible HIV exposure before taking a test. HIV will not appear on tests until at least 18 days after exposure.

Importantly, the HIV testing window differs for the types of HIV tests. These are:

  • antibody tests, which can detect HIV between 23 and 90 days after HIV exposure
  • rapid antigen/antibody tests, which can detect HIV between 18 and 90 days after HIV exposure
  • antigen/antibody lab tests, which can detect HIV between 18 and 45 days after HIV exposure
  • nucleic acid tests (NATs), which can detect HIV between 10 and 33 days after exposure

There are two main ways to test for HIV. These are clinic tests and self-tests.

At a clinic

The CDC notes that many healthcare professionals offer HIV testing. Often these come for free or for a reduced cost. Other places that might offer clinic HIV testing include:

  • community health centers
  • substance misuse programs
  • hospitals

The CDC provides a free tool for finding clinic HIV testing.

HIV self-testing

As the CDC explains, individuals can get HIV self-tests. These are available from pharmacies or online. The CDC has also created a free tool for finding HIV self-tests.

HIV self-tests are antibody tests. Some involve swabbing the gums for an oral sample before testing it in a private location.

These tests can provide results within 20 minutes. Others involve taking a tiny sample of blood by using a finger stick.

The individual can then test this sample at home. In some cases, they can also mail the sample to a laboratory.

HIV testing is important for many people. Indeed, some medical experts recommend routine HIV testing for almost all individuals between the ages of 13 and 75.

For many people within this group, one-time or occasional testing might be sufficient. However, some groups of people may want to consider getting tested for HIV frequently. These include:

  • sex workers
  • people with HIV symptoms
  • individuals in early pregnancy
  • those who inject drugs
  • males who have sex with males, especially if they are younger
  • people who have sex with those who:
    • inject drugs
    • are bisexual
    • have HIV or may have it

A positive HIV test indicates that someone might have HIV. A negative HIV test indicates that someone might not have HIV. These test results call for different responses.

The CDC says a positive antibody HIV test result does not always mean someone has HIV. Anyone with some such positive result requires follow-up testing.

If follow-up tests are also positive, the individual does have HIV. Alternatively, a single positive non-antibody HIV test result also means the individual has HIV. In either case, the individual can speak with a doctor to discuss treatment.

The CDC also explains that anyone with a negative HIV test result needs follow-up testing. In particular, they must take a test after the testing window for their initial HIV test.

If the follow-up test is also negative, then the individual does not have HIV, provided that they did not have exposure to HIV during this time.

Receiving a positive HIV test result can be challenging. During this period and after that, an individual may want to consider welcoming support from friends, family, and loved ones.

They may also find it helpful to look for HIV charities, associations, and support groups. provides a wealth of information about HIV and sexual health support.

This section answers some frequently asked questions about HIV tests.

Is 3 weeks too early a time to test for HIV?

Some tests can detect HIV within 10 days of exposure.

Can HIV symptoms appear in 3 days?

Symptoms of HIV usually arise at least 2 weeks after exposure.

How accurate is the HIV test after 4 weeks?

Some HIV tests can pick up 100% of HIV infections 4 weeks after exposure.

HIV is a serious sexually-transmitted disease. Testing for it in a clinic or at home can mean earlier treatment for those with it. It can also mean a lower risk of transmitting it to other people.

There are different HIV testing windows for HIV test types. For instance, antibody tests can detect HIV between 23 and 90 days after exposure. Contrastingly, NATs can detect HIV between 10 and 33 days after exposure.

Many experts believe that HIV testing is necessary for anyone who is potentially sexually active. However, some people may need more frequent testing. These include males who have sex with males, people who inject drugs, and sex workers. They also include anyone with HIV symptoms.

People whose sexual partners have HIV or whose sexual partners might have it may also want to consider getting tested frequently for HIV.