STD testing: What to know before your appointment

Not all doctors perform the same tests for sexually transmitted diseases, known as STD testing. Learn which tests you may need, which you might have to ask for and the limitations of STD testing.

Mary Gallenberg, M.D.

If you're sexually active, particularly with multiple partners, you've probably heard the following advice many times — use protection and make sure you and your partners receive routine STD testing. But what's included in routine STD testing? Not all doctors test for the same STDs. And some STDs — some of which can't be fully prevented by condom use — can't be tested for. So even if you ask your doctor to test you for everything, this doesn't mean that you or your partner will be screened for or clear of all STDs.

The only way to fully protect yourself against STDs is to abstain from sex. However, if you've decided to be sexually active, routine STD testing is important to managing your health. Mary Gallenberg, M.D., a specialist in obstetrics and gynecology at Mayo Clinic, Rochester, Minn., helps clarify what kinds of STD tests are important and how to ensure you get them.

If you're sexually active, what routine tests are most important?

For women:
At a minimum, get a Pap smear — a simple procedure that collects cells from your cervix to test for cancer or precancerous changes. This type of cancer can arise as a result of a human papillomavirus (HPV) infection — a common STD. Pap smears are recommended for women who are age 21 and older or no later than three years after a woman's first intercourse. If you're a woman between age 30 and 69, you may only need a Pap smear every two to three years if you've had three normal Pap smears in a row and have had no new sexual partners.

For men:
Centers for Disease Control and Prevention (CDC) guidelines don't suggest routine STD screening if you don't have any symptoms, unless your sexual practices include having sex with men.

If you are a man who has sex with men, annual screening for HIV, syphilis, chlamydia and gonorrhea is recommended. HIV and syphilis can be life-threatening if untreated, and chlamydia and gonorrhea can put you at greater risk of acquiring HIV and other STDs.

For men and women:
Also see your doctor for STD testing if you have any signs such as genital sores, including fluid-filled blisters, ulcerations or warts, or if you have unusual discharge from your penis or vagina. If you're a woman, abdominal pain or fever along with unusual discharge may indicate pelvic inflammatory disease (PID) — an STD-related condition that can cause infertility.

The CDC also encourages voluntary HIV testing, at least once, as a routine part of medical care if you are an adolescent or adult between the ages of 13 to 64. The CDC advises yearly HIV testing if you are at high risk of infection, for example if you've had unprotected sex with more than one sexual partner since your last screening.

What other STD testing do you recommend?

First, don't assume that during an annual exam or Pap smear that you're also receiving STD testing. This may not be the case. If you think you need STD testing, you must request it from your doctor. Talk to your doctor about your concerns and what tests you'd like or need.

Gonorrhea and chlamydia
If you are a sexually active girl or woman under age 24, or a woman older than 24 and at risk of STDs — for example you are having sex with a new partner or multiple partners — get screened annually for gonorrhea and chlamydia. If untreated, these infections can cause PID in women. Gonorrhea and chlamydia can also significantly increase your risk of acquiring other STDs like HIV. If you are a man who has sex with men, get tested for these infections at least annually.

Gonorrhea and chlamydia screening is either done through a urine test or through a swab inside the penis in men or from the inside of the cervix in women. The sample is then analyzed in a laboratory. Screening is important, because you can be unaware that you have either infection. For example, approximately 80 percent of women and 50 percent of men diagnosed with chlamydia don't have symptoms at the time of diagnosis.

Syphilis, hepatitis and HIV
If you test positive for gonorrhea or chlamydia, you're at greater risk of other STDs such as syphilis, HIV and hepatitis and should get tested for these infections.

In addition, request HIV, syphilis and hepatitis testing if you:

Have had more than one sexual partner since your last screening
Use IV drugs
Are a man who has sex with men
Are concerned you've been exposed

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 A and B.

It's possible that you may test negative for syphilis or HIV if you've only just recently acquired the infection. If you or your doctor suspects this is the case, you may need to be rescreened at a later date. Talk with your doctor if you have concerns about this.

Consider vaccination for hepatitis A and B. You can prevent these infections by receiving the vaccines.

What about other common STDs like genital herpes and human papillomavirus (HPV) infection?

Genital herpes
Unfortunately, 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 may also help detect a herpes infection, but, again, results aren't always conclusive, particularly if you're not experiencing signs and symptoms of an active stage. Some blood tests don't distinguish between types 1 and 2 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. You may ask for a "type-specific" IgG blood test, which differentiates between the two, measuring antibodies to the viruses in your blood. 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
HPV, an infection that can be transmitted even when a person doesn't have symptoms, is a condition contracted from one of a group of more than 100 related human papillomaviruses (HPVs). Some of the viruses cause cervical cancer, others cause genital warts. Some never cause any problems. At least 50 percent of sexually active men and women will acquire an HPV infection within their lives, and that number jumps to 80 percent of women by age 50.

Being infected with certain types of HPV is the most important risk factor for developing cervical cancer. Women over age 30 may choose to receive a Pap test (to test for cervical cancer) every three years along with a human papillomavirus (HPV) DNA test. The HPV test is collected with a brushing from the cervical canal. Women with both a negative Pap test and a negative HPV DNA test are at low risk of developing significant precancerous changes of the cervix over the next three years. The combination of Pap smear and HPV DNA testing is not Food and Drug Administration (FDA) approved for screening women younger than 30 because HPV infections that will ultimately clear up on their own are more common in this age group, and a positive test result may lead to unnecessary additional testing and treatment.

The HPV DNA test can test for both low-risk types of HPV, which may cause genital warts, and high-risk types that may cause cervical cancer. Your doctor may recommend testing only for the high-risk types because of their threat to your health. Since no treatments exist for HPV itself — although treatments do exist for genital wart outbreaks caused by HPV — paying for a test to find the low-risk types may be of little use to you.

No HPV test is available for men with the exception of visual inspection or biopsy of genital warts if they are present.

Girls and women ages 9 to 26 can help prevent HPV infection by receiving the HPV vaccine. This vaccine protects against the two strains that cause 70 percent of cervical cancers and the two strains that cause 90 percent of genital warts.

Are all STD tests always done?

No, as mentioned earlier, men should receive testing if they have symptoms, have sex with other men, or if a partner tests positive for an STD. In women, HIV, syphilis and hepatitis testing may be done if other STDs are present. Testing for herpes is only usually done if symptoms are present. And HPV testing isn't available for men, and only sometimes done for women older than 30.

Ask to be tested for other STDs if you're concerned. Some tests may be expensive and your insurance may not cover them.

What STD tests are commonly covered by insurance?

Insurance companies differ in what services are covered. Check with your insurer, and if STD testing isn't covered and you can't afford to pay, consider testing through your county public health clinic or your local Planned Parenthood clinic.

Many states have laws or programs to ensure that all eligible women receive a Pap smear, regardless of their income or ability to pay.

What do you suggest to someone considering having sex with a new partner or who may be at risk of an STD?

If you can't trust a partner not to give you an STD, you may not want to have sex with that person. You can ask them to be tested for gonorrhea, chlamydia, HIV, syphilis and hepatitis, but negative tests for these may mean the infection is just in too early of a stage to detect. Also, there are no good screening tests for herpes, and HPV testing is limited — men can't be tested unless they have visible warts, and HPV testing generally isn't recommended for women younger than 30.

If you decide to have sex, use condoms. Condoms help protect you against life-threatening infections like HIV. However, condoms don't fully protect you against every STD. For example, condoms may not cover all of the skin that might contain an HPV or herpes virus, so the condoms may reduce, but not eliminate, the chance of such a virus being transmitted to you. In fact, you can be exposed to these viruses through genital to genital or mouth to genital contact, not just through intercourse.

If you have sex, you put yourself at some risk even with the most thorough testing and condom use, and you have to accept that risk.

If a person tests positive for an STD, what's the next step?

If you test positive for an STD, the next step is to consider further testing and then to get treatment as recommended by your doctor. In addition, inform any 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. These are all normal feelings. Some STDs are very common so you aren't alone. You've done the right thing by getting tested and you can now discuss treatment and how this might affect current or future relationships. Talk with your doctor about your concerns.