What is an HIV test?
An HIV test shows whether you have the human immunodeficiency virus (HIV). HIV is a sexually transmitted infection (STI) that attacks your immune system, making it harder for your body to fight infections. In some — but not all —cases, HIV can lead to acquired immune deficiency syndrome (AIDS), which can be life-threatening.
Getting tested for HIV is important because the sooner you know about an infection, the sooner you can receive treatment. Current treatments for HIV can strengthen your immune system to fend off the virus more effectively. Early treatment can prevent you from developing AIDS.
Current HIV tests are highly effective at detecting HIV. Current protocols for HIV testing reliably lead to an accurate diagnosis.
What are the three tests for HIV?
To diagnose HIV, your healthcare provider can order any of three types of tests. Depending on the test, you’ll provide a blood sample (from a vein or a finger prick) or an oral fluid sample that can be tested for HIV. Oral fluid contains cells from your mouth. It’s different from saliva.
- Nucleic acid (NAT) test: The NAT test can detect HIV RNA, the genetic material in HIV. The test can also tell how much of the virus is in your blood (viral load). The NAT is a thorough lab test requiring a blood draw (a healthcare provider draws blood from a vein). It can be expensive.
- Antigen/antibody test: Combination antigen/antibody tests check for signs of the virus instead of the virus itself, as with the NAT test. First, it tests for antigens. An antigen is a substance that activates your immune system to fight HIV. If you have HIV, antigen p24 will be in your blood. The test also checks for HIV antibodies. Your immune system makes HIV antibodies to fight off the virus. Antigens show up in your blood before antibodies do.
- Antibody tests: This test checks for HIV antibodies.
Since a NAT test is more expensive, you’ll rarely take this test to screen for HIV unless you have symptoms. If you’re HIV-positive, your healthcare provider may order a NAT test to check your viral load, or how much of the virus is in your blood.
To screen for HIV, you’ll likely take an antibody test or a combination antigen/antibody test first. You’ll need follow-up testing if your results are positive to confirm the results.
When would an HIV test be needed?
The U.S. Preventive Services Task Force on HIV recommends that everyone between ages 15 to 65 take an HIV test at least once in their lifetimes. HIV doesn’t always cause symptoms in its early stages. An HIV test may be the only way to detect the virus and potentially prevent spreading it to others.
You should also get tested if you’re high-risk for HIV exposure or if you’re pregnant.
HIV testing for high-risk groups
HIV gets transmitted through body fluids exchanged during sex and through blood. You’re considered high-risk if it’s likely that you’ve been exposed to these fluids from a person who has HIV. Having unprotected sex (without a condom or dental dam) with an HIV-positive partner greatly increases your risk of HIV.
You may need regular HIV tests if:
- You have vaginal, anal or oral sex with an HIV-positive partner or a partner whose HIV status you don’t know.
- You have sex with more than one partner or your partners have sex with more than one partner.
- You’re a person with a penis who has sex with other people with penises (men who have sex with men, or MSM).
- You have a sexually transmitted infection other than HIV (Having an STI can make you more susceptible to contracting HIV).
- You share needles to inject drugs.
Getting tested regularly may mean that you take a test once a year or even more frequently. The Centers for Disease Control and Prevention (CDC) recommends that men who have sex with men get tested every three to six months. Ask your healthcare provider about how often you should get tested.
You should also get tested if you’re sexually assaulted. In these instances, contact a healthcare provider to get started on HIV post-exposure prophylaxis (PEP). PEP is a series of medicines that can prevent HIV. You have to begin taking them within 72 hours of a possible exposure for them to work.
HIV testing during pregnancy
An HIV test is recommended during pregnancy and preferably given during the first trimester of pregnancy since HIV can be passed between mother, or gestational parent, and fetus. HIV can also be passed through breast (chest) milk. Receiving treatment early in pregnancy can prevent you from transmitting the virus to your newborn.
If you’re pregnant and considered high risk for contracting HIV, you should be retested at least two to three times during pregnancy.
Where can I get an HIV test?
You have many options for testing sites (including your own home).
- You can get tested in your healthcare provider’s office, a clinic or a community health center.
- The CDC allows you to type your address into a search bar and locate testing sites for HIV and other STIs. Many of these sites offer free testing.
- You can search STI testing locations using the HIV Testing Sites & Care Services Locator.
- You can purchase an at-home HIV test kit in stores or online if you’re 17 or older. Currently, OraQuick® In-Home HIV Test is the only FDA-approved at-home HIV test on the market.
How does an HIV test work?
An HIV test looks for evidence of HIV in your blood or oral fluid. This evidence may be the virus itself, HIV antigens and antibodies, or just the antibodies. Additional testing will be needed to confirm the results if you test positive. If you test negative, this means that you likely don’t have the virus. To trust the results, you’ll need to be sure that you took the test at the right time to detect the virus. It takes some time after you’ve been exposed to the virus for an HIV test to detect it.
How soon after exposure to HIV can a test detect the virus?
HIV tests can’t detect HIV immediately after you’ve been exposed. It takes time for your body to make antibodies in response to the virus. The window period is the time gap between when you were exposed and when a test can detect the virus. You’ll want to get tested after the window period. The window period varies from person to person and by the type of test.
- A nucleic acid (NAT) test has the shortest window period. It can tell if you have an HIV infection from 10 to 33 days after exposure.
- Antigen/Antibody tests can detect infection from 18 to 45 days after exposure (for blood draw tests) or 18 to 90 days after exposure (for finger-prick tests).
- Antibody tests (most rapid and at-home tests) can detect infection 23 to 90 days after exposure.
If the test is negative and you feel you’ve been exposed, get retested.
How do I prepare for an HIV test?
You don't need to do anything to prepare for tests involving blood draws. For at-home tests that involve collecting oral fluid, you may need to avoid eating or drinking 30 minutes before taking the test. Follow the instructions on the kit.
What should I expect during the HIV test?
Your experience will depend on which test you take and where you take it.
Lab HIV tests
Most HIV tests involve a healthcare professional drawing blood and sending it to a lab for analysis. These tests may take place in your provider’s office or a clinic. If you test positive, your provider will do additional testing to confirm the results. The CDC recommends the following sequence of HIV tests:
- Test #1: An antigen/antibody test to check for HIV antigen p24 and HIV antibodies. You’ll need a second test to confirm the results if you test positive.
- Test #2: An antibody test to check for antibodies associated with the two types of HIV, HIV-1 and HIV-2. A second positive result will confirm that you’re HIV-positive. If the results are inconclusive, you’ll need to take a third test.
- Test #3: A NAT test to check for HIV in your blood.
This combination of testing is nearly 100% effective at diagnosing HIV.
Rapid HIV tests
Rapid tests check your blood or oral fluid for HIV antibodies. There is also a rapid HIV antigen/antibody test. A healthcare professional may collect blood using a blood draw from a vein or a finger prick. An oral fluid sample will require a mouth swab.
Some rapid tests can provide results in as little as five minutes. Keep in mind that these results are preliminary. If your result is positive, you’ll need to follow up with your healthcare provider to take an additional test before you’ll know your HIV status.
At-home HIV tests
The only FDA-approved at-home test is OraQuick®, a rapid HIV test that checks for HIV antibodies. To use it, you swab your upper and lower gums to collect a sample of oral fluid. You place the swab in a vial that shows a positive or negative result (similar to a pregnancy test). You can view results within 20 to 40 minutes.
If the results are positive, you’ll need additional testing to confirm the results.
What are the risks of this test?
An HIV test doesn’t involve any risks. You may feel discomfort during a blood draw or finger prick.
Results and Follow-Up
When should I know the results of the test?
How quickly you receive the results depends on the type of test. Some rapid tests, such as antigen/antibody and antibody tests, can produce results in under 20 minutes. The NAT test has the shortest window period for detecting HIV after an exposure. Still, it requires more waiting to get the results. You may have to wait several days to get results from the NAT test.
What type of results do you get, and what do the results mean?
Test results will be negative or positive.
- A negative result means that the test didn’t detect signs of the virus. These results may mean that you don’t have HIV or that it’s too soon since your HIV exposure for the test to detect the virus.
- A positive result means that the test did detect signs of the virus. These results may mean that you have HIV or that you’ll need additional testing to confirm results.
What should I do if my results are negative?
If your first test is negative and there’s a chance that you took the test too soon to detect HIV exposure, take a second test after the window period has passed. The second test can confirm your negative result if you got tested before the infection was active in your body.
Even with a negative result, it’s important to protect yourself in the future. Talk to your healthcare provider about whether PrEP (pre-exposure prophylaxis) is right for you. The PrEP daily pill can reduce your risk of getting HIV from sexual contact by 99%. For people who use IV drugs, it lowers the risk by 74%. Taking PrEP as prescribed is essential if you’re HIV-negative and your partner is HIV-positive.
Even if you take PrEP, it’s recommended that you use a condom or dental dam to reduce your risk of contracting HIV and other STIs.
What should I do if my results are positive?
If you get a positive result on one test, you’ll want to do additional testing with your healthcare provider to be sure. Once your diagnosis is confirmed, you’ll want to work with your provider on a treatment plan. Your healthcare provider will determine how far HIV has progressed and recommend medicines to help you manage it. Treatment for HIV, or antiretroviral therapy, can help your body fight the virus and prevent AIDS. Researchers are producing highly active drugs against the virus. If used consistently and correctly, they can prevent disease progression and enable you to live a healthy life.
You’ll also want to talk about your diagnosis with your sexual partner. If you and your partner have had unprotected sex, you could have transmitted the virus to them. They should get tested, too.
When should I take an HIV test?
You should take an HIV test at least once in your life — and even more if you’re at high risk of exposure. Be sure to take the test after the window period, when you can trust that the test can detect the virus.
Can a normal blood test detect HIV?
HIV blood tests involve simple blood draws that are the same as most blood tests. What makes an HIV test different is how your blood gets tested once it’s sent to the lab. Your blood will need to be tested specifically for signs of HIV, including antigens, antibodies or HIV RNA.
What is a normal HIV test result?
A negative HIV test result is considered normal.
What is the difference between an HIV-1 and an HIV-2 test?
There are two types of HIV: HIV-1 and HIV-2. Some antibody tests can detect whether you have HIV-1 or HIV-2 antibodies in your blood (or both). HIV-1 is the most common type of HIV and is more easily transmissible than HIV-2.
A note from Cleveland Clinic
If you’re concerned that you may be HIV positive, rally your support network. Talk to friends and family members you trust. Speak to a counselor or therapist who can help support you as you anticipate taking the test and receiving the results. Getting a positive result can be scary, but it’s worth it to know for sure so that you can inform sexual partners and begin treatment. Treatments for HIV have advanced significantly since the virus was first discovered in the 1980s. Many people currently living with HIV enjoy healthy lives.
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