STDs (sexually transmitted diseases) are infections that are mostly spread through sexual activity, including vaginal, oral, and anal sex. Some infections can be spread through close personal contact, such as kissing, or from a mother to her unborn child.

STDs are caused by bacteria, viruses, or parasites. Millions of Americans are infected with some type of STD every year, with half of the diagnoses occurring in teens and young adults between the ages of 15 and 24. Common STDs include chlamydia, gonorrhea, genital herpes, HIV, and HPV (human papillomavirus) infection.

Left untreated, certain STDs can cause devastating and long-term health problems such as blindness, brain damage, infertility, birth defects, and even death. Fortunately, all STDs can be treated, and some can be cured entirely. STD testing can help you get diagnosed and treated so you may avoid serious complications.

Other names: STD screening, STI (sexually transmitted infections) test, STI screening

What are they used for?

STD tests are used to find out if you have been infected with an STD. Testing can help you get the treatment you need and may help prevent the spread of disease.

Why do I need an STD test?

STDs don’t always cause symptoms, so it is possible to catch or spread an infection even if you or your partner seem healthy. So, you may need an STD screening test if you are at higher risk for infection. Screening is a type of test done for people who don’t have symptoms.

While all sexually active people could potentially get an STD, testing is mostly recommended for people who fall in one or more of the following risk categories:

• Sexually active women under the age of 25. Experts recommend that women in this age group get a chlamydia test and a gonorrhea test every year. Sexually active women 25 years and older should be tested if they have new or multiple sex partners or have a partner who has been diagnosed with an STD.
• Women 21 years and older. Women in this age group should get a Pap smear to check for abnormalities in the cervix. These include precancerous changes which can be caused by HPV (human papillomavirus).
• Pregnant women. Pregnant women are usually tested for HIV, hepatitis B, chlamydia, and syphilis. Pregnant women with certain risk factors may also be tested for gonorrhea and hepatitis C.
• Sexually active men and women who have unprotected sex and are not in monogamous relationships. A monogamous relationship means having only one sexual partner at a time.
• People who have sex without a condom should be tested regularly for HIV and other STDs as recommended by their provider.
• Men who have sex with men. Compared with other groups, men who have sex with men have a higher risk of STDs. Men in this group should be tested at least once a year for syphilis, chlamydia, gonorrhea, and HIV. Men with multiple partners may benefit from more frequent testing.
• People with HIV. If you have HIV, you are at a higher risk of getting another STD. People in this group should be tested for syphilis, gonorrhea, and herpes. A chlamydia test is also usually recommended.
• People who use injectable drugs. Sharing needles puts you at risk for HIV. Regular HIV testing is recommended for this group.

Some STDs do cause symptoms. Symptoms vary depending on the type of STD, but you may need testing if you have one or more of the following symptoms:

• Painful urination
• Pain during sex
• Unusual odor in vaginal discharge
• Vaginal itching
• Discharge and/or itching from the penis
• Sores or bumps in the genital or rectal area

What happens during an STD test?

Depending on the type of suspected infection, you may get one of the following types of tests:

Blood tests

• Used to diagnose syphilis, HIV, and sometimes herpes
• During the test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial

Urine tests

• Used to diagnose trichomoniasis and sometimes gonorrhea
• During the test, you will provide a sterile sample of urine in a cup as instructed by your provider

Swab tests

• Used to diagnose HPV, chlamydia, gonorrhea, and herpes
• During the test, a provider will use a special swab to take a sample from the site of the infection. In women, samples may be taken from the vagina or cervix. In men, samples may be taken from the penis or urethra, the tube that carries urine out of the body.

Lumbar puncture, also known as a spinal tap

• This is not a frequently used STD test, but it may be ordered if your provider thinks you have an advanced stage of syphilis or if a herpes infection has affected your brain or spinal cord.
• For this test, a provider will inject an anesthetic into your back, so you won’t feel any pain during the procedure.
• Once the area is numb, the provider will insert a thin, hollow needle between two vertebrae in your lower spine. Vertebrae are the small bones that make up your spine. Your provider will then withdraw a small amount of fluid for testing.

You may also be able to check for STDs with an at-home test. Home test kits are available for several STDs, including chlamydia, gonorrhea, syphilis, trichomoniasis, and hepatitis C.

• These tests usually involve using a device (lancet) to prick your finger for a drop of blood, collecting a urine sample, or taking an oral swab. You should discuss your at-home STD test results with your provider to see if you need further testing and/or treatment.

Will I need to do anything to prepare for the test?

You don’t need any special preparations for a blood test. If you’re a woman, you may need to avoid douches and vaginal creams for 24 hours before a urine or swab test.

You may need to empty your bladder before a lumbar puncture.

Your provider will let you know if you need to make any other preparations.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruise at the spot where the needle was put in, but most symptoms go away quickly.

There are no known risks to having urine or swab tests.

If you had a lumbar puncture, you may have pain or tenderness in your back where the needle was inserted. You may also get a headache after the procedure. The headache can last for several hours or up to a week or more.

What do the results mean?

The test result will show whether you have an STD. If you are diagnosed with an STD, there is no need to feel embarrassed or ashamed. STDs affect millions of people.

If you have an STD, be sure to take the medicine as prescribed by your provider. It’s also very important that you tell your partner, so they can get tested and treated if necessary.

Is there anything else I need to know about STD tests?

The best way to prevent an STD infection is to not have sex. If you are sexually active, you can reduce your risk of infection by:

• Being in a long-term relationship with one partner who has tested negative for STDs
• Use latex condoms correctly every time you have sex. If you or your partner is allergic to latex, you can use polyurethane condoms.