HIV Testing and Screening

Medically Reviewed by Zilpah Sheikh, MD on July 30, 2024
Written by Stephanie Watson, Shawna Seed
12 min read

HIV testing, also called HIV screening, is the only way to know if you have the virus.

Several types of tests check your blood or other body fluids to see whether you're infected. Most can't spot HIV right away because it takes time for your body to make antibodies or for enough of the virus to grow inside you.

If you have HIV, finding out quickly means you can start treatment right away so you can feel better and live a long, full life. You can also take steps so you don't pass HIV to other people.

If you're pregnant, you should get tested because early treatment means you probably won’t pass it to your baby. Testing is recommended during your first trimester. If you're considered high risk for HIV, you'll want to have HIV testing several times during your pregnancy. 

The CDC recommends that everyone in the United States between the ages of 15 and 65 get tested for HIV at least once.

You should be tested more often -- at least once a year -- if you’re at higher risk of getting HIV, including if you:

  • Have had several sexual partners since your last HIV test
  • Had unprotected sex with someone who is or could be HIV-positive, including someone whose sexual history you don't know
  • Injected drugs using a needle, syringe, or other device that someone else used first
  • Have had or are getting tested for tuberculosis, hepatitis, or any sexually transmitted disease, including syphilis, gonorrhea, chlamydia, or herpes
  • Have exchanged sex for drugs or money
  • Had sex with someone who has a history of any of these things
  • Have been sexually assaulted

 

There are two basic ways to get HIV test results:

Laboratory tests

For these tests, a technician takes a sample of your blood and tests it. You’ll get results within a few days.

Rapid tests

These tests provide results in about 20-30 minutes. You can get them done in a community clinic or take them at home.

If you’ve had a high-risk exposure to HIV very recently, go to the emergency room or call your doctor right away. Examples include unsafe sex with someone who has HIV or if you were sexually assaulted. 

Ask your doctor about getting tested for HIV. For most types of HIV tests, you’ll need to wait 2 weeks or more after exposure to get an accurate result. You can infect others soon after you're exposed, so practice safe sex and take other precautions in the meantime.

Almost everyone who is HIV-positive has detectable levels of antibodies at 3 months. So if you test negative a month or two after your exposure, your doctor may want you to retest after 3 months to be sure.

Post-exposure prophylaxis

If you believe you've been exposed to HIV, you should see a health care provider within 72 hours. They can prescribe a series of medicines that together are called HIV post-exposure prophylaxis, known as PEP.  If you begin taking the medicine within 72 hours of being exposed, PEP can prevent HIV infection. You'll need to take antiretroviral medication for 28 days.

Every HIV test has a different “window period.” That’s how long you need to wait after exposure until you can expect an accurate result. No HIV test can tell if you have the virus just after you’ve been exposed.

If you get tested too soon, you may get faulty results. But if you wait too long to learn if you’re HIV-positive, you can miss out on early treatment and also unknowingly spread the virus to others.

Standard HIV blood test

This test uses blood that a technician takes from your vein and sends to a lab. It can find antibodies (proteins your immune system makes when you’ve been exposed to the virus) 23-90 days after infection.

Rapid blood test

This test looks for antibodies using a drop of blood from a prick of your fingertip. It’s about as accurate as the original antibody test, but its window period could be longer -- between 18 and 90 days. Your health care provider can do this test, or you can buy a kit that lets you mail your sample in for testing.

 

Antibody/antigen test

These tests look for both antibodies and an antigen, a substance the virus makes before your immune system can start making antibodies. An antibody/antigen test that uses blood taken from a vein can find HIV 18-45 days after you’re exposed to the virus.

Newer antigen/antibody combination tests (you might hear them called “fourth generation” tests) can find HIV in 99% of people who are tested within 13-42 days of exposure. This test has become the standard HIV blood test in most labs.

A rapid antibody/antigen can also be done using blood from a prick of your fingertip. A health care provider can do this test. Or you can use a mail-in kit. The window period for this test is 18 to 90 days.

Rapid oral test

You can do this quick, easy test at home. You'll swab the area between your gums and teeth to collect a sample of oral fluid (it isn’t the same as saliva). The test looks for antibodies against HIV. If you’ve had the virus for a while, the rapid oral test is highly accurate. But if you have a new infection, even if you got it in the past few months, the test won’t be as reliable. The window period is 23 to 90 days. 

Urine test

These also look for HIV antibodies, but they aren’t as accurate as other tests that check either your blood or oral fluid. Because it’s an antibody test, its window period is similar to that of a standard HIV test.

Nucleic acid tests (NAT)

These tests look for HIV about 10-33 days after infection. They look for signs of the virus itself, not antibodies to it. You may also hear this called an HIV RNA or a viral load test. It uses blood taken from a vein. You probably won’t get this expensive test unless you have symptoms and the doctor thinks you have a recent infection. It’s most often used to see how people who already have HIV respond to treatment.

A health care provider can advise you on how often to test and what type of test to use based on your personal situation. 

For a lab test, you might need to call your doctor to schedule it. Some public health clinics take walk-ins.

A technician will take a small blood sample and send it to a lab. Some immunoassay tests check your urine or fluids from your mouth (not saliva), but there aren't as many antibodies in these, so you may get false results.

With home blood tests, you prick your finger to get a small blood sample that you send to a lab. You call to get your result, and you don't have to give your name. If it's positive, the lab will also do a follow-up test to double-check.

With home oral fluid tests, you swab your upper and lower gums and test the sample in a vial. About 1 in 12 people who are infected get a false negative from this test. If it’s positive, get a lab test to confirm.

How long does it take to get HIV results?

This depends on what kind of test you had. Rapid tests provide answers in less than 30 minutes. With a standard blood test or antibody/antigen test, you should expect results in a few days. It may take several days to get results from an NAT test. Urine test results could take up to 2 weeks.

Some tests are anonymous, meaning your name isn’t tied to the result. Others are confidential: Your information is attached to the result, but it’s protected by privacy laws.

Positive test results

A positive test result means there are traces of HIV in your body. Health care providers never diagnose HIV based on a single test result. If you had a rapid test, get a standard lab test to confirm it. If you had a lab test, more detailed tests of your blood can confirm your diagnosis:

  • Western blot or indirect immunofluorescence assay
  • Antibody differentiation between HIV-1 and HIV-2

A positive HIV test doesn’t mean you have AIDS, the most advanced stage of the disease. HIV treatment can keep you from getting AIDS, so talk to your doctor right away about starting medications called antiretroviral therapy (ART). These drugs lower the amount of the virus in your body, sometimes to a point where a test can’t find it. They also protect your immune system so your HIV infection doesn’t become AIDS.

False-positive test results

Some HIV tests have a very slight chance of giving you false results. A “false-positive” result means the test shows you have HIV when you don’t. This occasionally happens when your test detects antibodies but they’re antibodies to another infection or substance, not to HIV. Rarely, a false positive can result from a lab mix-up or misinterpretation.

The rapid oral fluid test is more likely to give you a false-positive result than other tests. If you get a positive result on a rapid oral test, your doctor will give you a blood test to confirm your diagnosis.

Negative test results

If your result is negative, you can take steps to protect yourself from HIV. They include practicing safe sex and taking medicine called pre-exposure prophylaxis (PrEP). This is different from PEP. PrEP is only for people who do not have the virus. 

Even if your test is negative, your partner could still have the virus. Talk with them about getting tested.

It could take as long as 6 months for you to have enough antibodies to get a positive result on some tests. If it’s been 3 months or less since you might have been infected and your test result is negative, get another test at 6 months to be sure.

False-negative test results

It’s also possible to get a “false-negative” result. That means the test says you don’t have HIV, but you do. This may happen if you get tested before or early in the window period for your particular test.

It also sometimes happens in people taking antiretroviral medicine for PrEP or PEP.  Otherwise, it’s very rare to get a false negative after the window period.

Where you get tested for HIV depends on what’s available in your area, how much you can spend, and your preferences. Among the places that offer testing are:

  • Health clinics and community health centers
  • County health departments
  • STD and sexual health clinics
  • Family planning clinics
  • Substance abuse treatment and prevention programs
  • LGBTQ+ health centers
  • VA medical centers
  • University health centers
  • Pharmacies
  • Private doctors’ offices

Testing through local health departments and college health centers is often free. Some nonprofits also offer free or low-cost testing.

If you test positive, these organizations can help you get treatment. If you test negative, they can tell you about ways to prevent HIV infection.

At-home testing kits are available online and at pharmacies without a prescription. They generally offer you access to telephone counseling before and after testing.

To find out where you can get tested, check hiv.gov or gettested.cdc.gov, or call 800-CDC-INFO (800-232-4636).

Research has shown that some people avoid getting an HIV test because they fear others’ negative attitudes about HIV. This stigma results largely from fear, outdated beliefs about how HIV is transmitted, and value judgments about people who have it.

People may think an HIV diagnosis could:

  • Affect their relationships with friends and family
  • Cause problems with housing, employment, or school
  • Keep them from getting health care or health insurance  

Other barriers to HIV testing include economic, cultural, and social issues such as:

  • Lack of access or transportation to testing
  • Homophobia
  • Racism
  • Discrimination against trans people

And of course, it’s common to be afraid of getting a positive test result. But learning your status can relieve the anxiety of uncertainty.   

If you don’t feel comfortable going to your regular doctor, consider testing by a nonprofit group or community health center. Some serve particular populations, such as LGBTQ+ people. They may even offer mobile testing vans. Or you may prefer to self-test in the privacy of your home.

You can also take the test at home yourself. Here’s how to do it and what you should know about self-testing.

HIV home test kits

Home Access HIV-1 Test System: With this over-the-counter kit, you prick your finger and put a drop of blood on special paper. You then mail the sample to a testing lab. You need to wait about a week before you call a toll-free phone number for your results using your anonymous personal identification number. You’ll also be offered counseling by telephone if you need it.

OraQuick In-Home HIV Test: You can buy this test online or at a pharmacy. This quick-result test checks for HIV antibodies in a sample of saliva. You swab your upper and lower gums with a test stick. You then insert the sample into a vial filled with a fluid, wait 20-40 minutes, and read the result.

HIV home test accuracy

The Home Access HIV-1 Test System is extremely reliable. Studies show that it will detect HIV antibodies more than 99.9% of the time. When your sample gets a positive result, the lab will confirm it with another test before you can call for your result.

The test is also 99.9% accurate if your results are negative, meaning that you don’t have HIV. So you can be highly confident of either answer.

The OraQuick In-Home HIV Test is less accurate. This test will find HIV antibodies 92% of the time. That means it will miss an HIV infection in 1 of 12 people who have it. OraQuick rarely gives false positive results, meaning that it’s unlikely to say you have HIV if you don’t.

But experts recommend that if you test positive on OraQuick, you should view the results as preliminary. You should confirm it with a second test from your doctor or a medical clinic so that you can get the care you need.

For both of these tests, if you test negative, you may want to get tested again if you’ve done anything recently that could have exposed you to the virus. It can take 3-6 months for your body to make HIV antibodies, so taking a test before or during this window period may miss an infection.

Best HIV Test for You

Should you get screened for HIV at a clinic or your doctor’s office, or take the test yourself? And which home test is best for you? The answers to these questions may help you decide:

  • How important is it that no one else knows that you’re taking the test or its results?
  • How important is accuracy?
  • Are you willing to get a follow-up test if needed?
  • How quickly do you want to get your results?
  • How do you want to receive your results?

If you’re at risk for HIV, any test is better than no test. A study of men who have sex with men who received self-tests in the mail found that they were likely to be screened for HIV more often. So the tests caught more HIV infections. The men who tested positive also shared the information with others they knew.

An HIV test can tell you whether you have the human immunodeficiency virus. Experts recommend that everyone in the U.S. between the ages of 15 and 65 get tested at least once. It's especially important to test if you're in a high-risk group or pregnant. The sooner you find out about an HIV infection, the sooner you can begin treatment. If you think you've been exposed to HIV, there are treatments you can start in the first 72 hours that will protect you against infection. There are several kinds of HIV tests available, including some you can take at home. 

How is an HIV test done?

There are several types of HIV tests. A health care professional can perform a test on blood taken from your arm or by pricking your finger. Labs also can test a sample taken from your mouth or urine. For at-home tests, you have to prick your finger or swab your mouth. 

Which HIV test is most accurate?

The antibody/antigen test, which uses blood taken from a vein, is most accurate. 

What does informed consent for HIV testing mean?

You've probably received a consent form to read and sign during a health care visit. That's called informed consent. The CDC recommends that you be able to opt out of HIV screening if you choose. It also recommends that HIV testing be part of the routine consent form rather than a separate form. The CDC states that you should never be tested for HIV without your knowledge.

What does it mean when an HIV test says non-reactive?

A non-reactive test means the screening found no sign of the HIV virus. It's the same as a negative test. But if you think you may have been exposed to HIV in the month before your test, ask your health care provider about testing again. 

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