Sexually transmitted diseases are common, but the types of STD testing you need may vary by your risk factors. Find out what's recommended for you. By Mayo Clinic Staff

If you're sexually active, particularly with multiple partners, you've probably heard the following advice many times: Use protection and make sure you get tested.

This is important because a person can have a sexually transmitted disease without knowing it. In many cases, no signs or symptoms occur. In fact, that's why many experts prefer the term sexually transmitted infections (STIs), because you can have the infection without disease symptoms.

But what types of STI testing do you need? And how often should you be screened? The answers depend on your age, your sexual behaviors and other risk factors.

Don't assume that you're receiving STI testing every time you have a gynecologic exam or Pap test. If you think you need STI testing, request it from your doctor. Talk to your doctor about your concerns and what tests you'd like or need.

Here are some guidelines for STI testing for specific sexually transmitted infections.

Chlamydia and gonorrhea

Get screened annually if:

  • You're a sexually active girl or woman under age 25
  • You're a woman older than 25 and at risk of STIs — for example, if you're having sex with a new partner or multiple partners
  • You're a man who has sex with men
  • You have HIV
  • You've been forced to have intercourse or engage in sexual activity against your will

Chlamydia and gonorrhea screening is done either through a urine test or through a swab inside the penis in men or from the cervix in women. The sample is then analyzed in a laboratory. Screening is important, because if you don't have signs or symptoms, you can be unaware that you have either infection.

HIV, syphilis and hepatitis

The Centers for Disease Control and Prevention (CDC) encourages HIV testing, at least once, as a routine part of medical care if you're an adolescent or adult between the ages of 15 and 65. Younger teens should be tested if they have a high risk of an STI. The CDC advises yearly HIV testing if you are at high risk of infection.

Hepatitis C screening is recommended for everyone born between 1945 and 1965. The incidence of hepatitis C is high in this age group, and the disease often has no symptoms until it's advanced. Vaccines are available for both hepatitis A and B if screening shows you haven't been exposed to these viruses.

Request testing for HIV, syphilis and hepatitis if you:

  • Test positive for another STI, which puts you at greater risk of other STIs
  • Have had more than one sexual partner since your last test
  • Use intravenous (IV) drugs
  • Are a man who has sex with men
  • Are pregnant or planning on becoming pregnant
  • Have been forced to have intercourse or engage in sexual activity against your will

Your doctor tests you for syphilis by taking either a blood sample or a swab from any genital sores you might have. The sample is examined in a laboratory. A blood sample is taken to test for HIV and hepatitis.

Genital herpes

No good screening test exists for herpes, a viral infection that can be transmitted even when a person doesn't have symptoms. Your doctor may take a tissue scraping or culture of blisters or early ulcers, if you have them, for examination in a laboratory. But a negative test doesn't rule out herpes as a cause for genital ulcerations.

A blood test also may help detect a herpes infection, but results aren't always conclusive. Some blood tests can help differentiate between the two main types of the herpes virus. Type 1 is the virus that more typically causes cold sores, although it can also cause genital sores. Type 2 is the virus that more typically causes genital sores. Still, the results may not be totally clear, depending on the sensitivity of the test and the stage of the infection. False-positive and false-negative results are possible.

HPV

Certain types of human papillomavirus (HPV) can cause cervical cancer while other varieties of HPV can cause genital warts. Most sexually active people become infected with HPV at some point in their lives, but never develop symptoms. The virus typically disappears within two years.

No HPV screening test is available for men, in whom the infection is diagnosed only by visual inspection or biopsy of genital warts. In women, HPV testing involves:

  • Pap test. Pap tests, which check the cervix for abnormal cells, are recommended every three years for women between ages 21 and 65.
  • HPV test. Women over 30 may be offered the option to have the HPV test along with a Pap test every five years if previous tests were normal. Women between 21 and 30 will be given an HPV test if they've had abnormal results on their Pap test.

HPV has also been linked to cancer of the vulva, vagina, penis, anus, and mouth and throat. Vaccines can protect both men and women from some types of HPV, but they are most effective when administered before sexual activity begins.

Gaining acceptance and popularity are at-home test kits for certain STIs, such as HIV, chlamydia and gonorrhea. For home STI testing, you collect a urine sample or an oral or genital swab and then send it to a laboratory for analysis. Some tests require more than one sample. The benefit of home testing is you're able to collect the sample in the privacy of your home without need for a pelvic exam or office visit.

However, tests done on samples you collect yourself may have a higher rate of false-positive results, meaning the test indicates you have an STI that you really don't have. If you test positive from a home test, contact your doctor or a public health clinic to confirm the test results. If your home test results are negative, but you're experiencing symptoms, contact your doctor or a public health clinic to confirm the results.

If you test positive for an STI, the next step is to consider further testing and then get treatment as recommended by your doctor. In addition, inform your sex partners. Your partners need to be evaluated and treated, because you can pass some infections back and forth.

Expect to feel various emotions. You may feel ashamed, angry or afraid. It may help to remind yourself that you've done the right thing by getting tested so that you can inform your partners and get treated. Talk with your doctor about your concerns.

Sep. 23, 2014