The Facts
Chlamydia is the most common sexually transmitted disease (STD) in North America, affecting both men and women, although women report the disease approximately three times as often as men. The infection is named after the bacterium that causes it, Chlamydia trachomatis. Most women who are infected with the bacteria have no symptoms and therefore don't know they have chlamydia. It's easily treated, but can sometimes lead to serious complications if it isn't caught early enough. For example, it is estimated that 20% to 25% of untreated women will develop pelvic inflammatory disease (PID), which can be very painful. The risk of abnormal pregnancies or infertility also increases with an untreated chlamydia infection.