What sexually transmitted disease (STD) can have no symptoms and make you sterile (unable to have kids)? 

What is one of the most common bacterial STD in the United States, especially among sexually active teens and young adults?

What STD is six times more common than herpes?

The answer is chlamydia, a bacterial infection that is transmitted mainly through vaginal and anal intercourse. It can also be passed through oral sex.

Each year, three million Americans get chlamydia. Forty percent of reported cases occur in teens between the ages of 15 and 19 years old, according to Linda Alexander, Ph.D., president of the American Social Health Association (ASHA) in Research Triangle Park, NC.

Chlamydia Is a…What?

Despite its alarming frequency, most teens don’t know anything about this STD.  Here are some common responses from teens to the question, “What is chlamydia?”

“Chlamydia—wait, what? I have no idea what that is,” says Elisa Shayne, 16, of Plainsboro, NJ.

“I know it’s an STD,” says Laura Hanne, 18, of San Diego, CA. “But I don’t really know much else. I don’t think many teens get it.”

“Chlamydia? It’s an STD, right?” asks Tyler Graffton, 15, of Pittsburgh, PA.

What’s alarming is that chlamydia’s main targets are teens like these, who know so little about it. 

And perhaps the most dangerous thing about chlamydia is that many teens don’t even know when they have it, because there are usually no symptoms. In fact, up to 85 percent of women and 40 percent of men show no symptoms, according to ASHA. 

“When you have a cold, your nose runs. When you have an allergic response to poison ivy, you itch. But you can have chlamydia and feel fine,” says Alexander. “But if left untreated, chlamydia can cause a number of adverse health problems, including pelvic inflammatory disease and sterility in women, and scarring of the urethra and sterility in men.”

If there are symptoms, the most common ones are abnormal discharge (mucus or pus) from the vagina or penis, and pain during urination. Early signs of infection are usually very mild, and will appear one to three weeks after being infected by a partner.  

A doctor or health care provider can diagnose chlamydia through a urine test or by taking a specimen from the infected area. The cost of a test will vary according to the facility. 

Alexander urges teens to call the National STD Hotline for help locating free or low-cost test sites, if they’re available in their area.

Chlamydia is easily cured with antibiotics. Both infected partners need to be treated at the same time.

Staying Healthy

“The most important thing for teens to know is that they, too, can become infected with an STD. Abstinence is the only sure method of prevention, but the consistent and correct use of latex condoms plays an important role in the personal prevention strategy of someone who’s unable or unwilling to practice abstinence. Teens need to know what puts them at risk and how they can protect themselves,” says Alexander.

So, if you choose to be sexually active, make sure you know your partner well, and get tested for STDs before becoming sexually intimate. If you think you might have been exposed to an STD, or are experiencing symptoms, consult a doctor or health care provider and get tested. Above all, be informed.

“Education is the strongest tool in STD prevention, and it’s important for teens to know that information is available to them,” urges Alexander.

Editors’ Note: If you have questions about chlamydia or any STD, call the Centers for Disease Control and Prevention’s National STD Hotline, 24 hours a day/7 days a week, at 1-800-227-8922 (English); or 1-800-344-7432 (Spanish).