Chlamydia is the most common bacterial sexually transmitted disease. Chlamydia can be treated with antibiotics. But if you don't know you're infected, you won't get treatment. If you have had sex, see your doctor and get checked. If treatment is delayed, infected women can get Pelvic Inflammatory Disease (a serious complication of Chlamydia). PID can cause problems now (abdominal pain) and problems later (difficulty getting pregnant or infertility). Most people infected with Chlamydia, especially women, don't have symptoms, so they can't tell. Even without symptoms, infected people can pass Chlamydia to every person they have sex with. When people with Chlamydia do have symptoms, the symptoms may include pain when going to the bathroom or a discharge coming from the penis or vagina.