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Sexual Conditions Health Center

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Could I Have an STD and Not Know It?

Why You Need to Know

STDs are common. There are about 20 million new cases of STDs in the U.S. each year. More than half of adults will have one in their lifetime. If you haven't been tested, you could pass an STD on to someone else. Even though you don't have symptoms, it can be dangerous to your health and the health of your partner.

Some STDs, including chlamydia and gonorrhea, can cause infertility. This is especially true for women. These diseases can cause pelvic inflammatory disease (PID), an infection of the uterus and other reproductive organs. PID can raise a woman's risk for ectopic pregnancy, a pregnancy outside the womb.

Other STDs, such as syphilis and HIV, can be deadly. Left untreated for years, syphilis can also seriously damage your brain, nervous system, and heart.

Certain strains of HPV can cause cervical cancer in women, cancer of the penis in men, and cancer of the anus in both men and women.

When to Get Tested

According to the CDC, how often you should get tested depends on several things:

  • Your age
  • Your gender (Women are tested more often than men because their risk of infertility is higher.)
  • Whether you have more than one sex partner or have a new sex partner
  • If you're pregnant
  • If you're a man who has sex with men
  • If you have unsafe sex (sex without condoms or that exposes you to a partner's blood, semen, or vaginal fluids)
  • If you share injection drug supplies

If you've never been tested but have been sexually active, there's no time like the present.

"You could have been exposed many years ago and still be infected, so you can still transmit it to someone else," says Teresa T. Byrd, MD. She's an assistant professor of obstetrics, gynecology, and reproductive sciences at University of Texas Medical School at Houston.

Some STDs may take a while to show up, Byrd says. "You may have to repeat certain tests at 1 month and 3 months."

STD Testing

Different STDs have different tests. "It is important to discuss the types of sexual activities you have had. That will direct the doctor in which test to use," Klausner says. You may need to give a blood or urine sample, or get swabs from your genital areas or mouth.

"Your doctor should check all potentially exposed sites. If you've had anal sex, your doctor should check your rectum. If you've had oral sex, your doctor should check your throat," he says. "There are also some swab tests you can do yourself."

Never assume that your doctor automatically checks for STDs when you visit. "Just because you are getting a Pap smear [or blood test], that doesn't mean you are getting tested for everything," he says. "You have to ask which test you are getting. If you're worried and you think you need a test, ask for it."

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Reviewed on August 11, 2014

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