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When to test for HIV

HIV testing should be part of your regular health routine if you are having sex or sharing needles to inject drugs.

If you think you might have been exposed to HIV, see a healthcare professional right away to get tested and talk through what’s next. Don’t wait for symptoms to appear – not everyone has them.

Even if you don’t think you have been at risk, testing regularly is good practice for people who are having sex.

How often should I test for HIV?

Test for HIV at least once a year if you’re having sex, even if you always use protection. It is a good idea to test more regularly than this if you have sex with a new partner. If you tested negative before but think you may have been exposed to HIV more recently, take another test.

I haven’t got any signs or symptoms of HIV. Should I still test?

Yes. The signs or symptoms of HIV can vary from person-to-person, and some people may not have any symptoms at all. It is important to test whether you have symptoms or not.

When should I test if I think I have been exposed to HIV?

Speak to a healthcare professional immediately. They will talk to you about your situation and help you decide what to do next. The most important thing is to take a test. Read the next question to find out how long you will need to wait after you were exposed to HIV before you can test.

It’s important to speak to a healthcare professional immediately because you could get PEP (post-exposure prophylaxis) if it is within 72 hours of when you think you were exposed to HIV. This is emergency HIV treatment that can prevent HIV in people who were recently exposed to HIV.

PEP

How long do I need to wait after exposure to HIV before I can test?

It takes a bit of time for HIV to show up in an HIV test – this is called the window period. The length of the window period will depend on the type of test you take. For some tests it is up to three months and for other tests it is one month.

Read more about window periods in the ‘In detail’ tab.

How many HIV tests do I need to confirm my status?

In some countries you will need two tests to confirm your HIV status. In other countries you will need three. This is to make sure that any false results are caught and confirmed with another test.

When should I test for HIV if I’m pregnant or planning to get pregnant?

Test regularly if you or your partner is pregnant, breastfeeding or planning to get pregnant. The earlier you test during pregnancy the better. You'll usually be tested in your first appointment, ideally before your tenth week. These tests should be repeated every three months or at least once again in your third trimester.

HIV testing during pregnancy

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What is a window period?

The window period is the time it takes for HIV to show up in an HIV test after someone has been exposed to HIV. The length of the window period will depend on the type of test taken.

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The picture above shows the window periods for different HIV tests. Some tests (fourth generation tests) can give an accurate result within four weeks. Others can take three months to be accurate (third generation tests, rapid tests and self-testing kits).

Healthcare workers will be able to explain how long the window period is for the test they offer. If you test before the window period is over, you will need to test again to get an accurate test result after the window period.

People who take pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP) may have a longer window period. This is because of a delay in their body’s response to HIV.

Why is more than one HIV test needed to diagnose someone?

False HIV test results can happen, although they are rare. This is why more than one test is needed to diagnose HIV. 

To avoid situations where people are misdiagnosed with HIV, the World Health Organization (WHO) is encouraging countries with HIV prevalence below 5% to increase the number of tests used to confirm an HIV diagnosis from two to three.

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  • Last updated: 18 March 2022
  • Last full review: 01 March 2022
  • Next full review: 01 March 2025
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