This page answers basic questions about chlamydia, including how to prevent and treat it. What is chlamydia? Chlamydia is a sexually transmitted infection spread by having unprotected sex with someone infected with bacteria called Chlamydia trachomatis. These bacteria are found in the urine and genital secretions of infected people. Chlamydia is a common sexually transmitted infection that can occur in both men and women. It is caused by a bacterium called Chlamydia trachomatis. It is easily treated and cured with antibiotics. Chlamydia is unlikely to lead to any long-term problems if treated early. What is Chlamydia? Chlamydia is a bacterial infection that’s easily cured with antibiotic medicine. It’s one of the most common STDs, and most people who have chlamydia don’t show any symptoms. To detect chlamydial infection, health care providers frequently rely on screening tests. Chlamydia is a common sexually transmitted infection (STI). It is caused by bacteria called Chlamydia trachomatis. Anyone can get chlamydia. It often doesn't cause symptoms, so people may not know that they have it. Antibiotics can cure it. But if it's not treated, chlamydia can cause serious health problems. How is chlamydia spread? Chlamydia is a common sexually transmitted infection (STI) caused by bacteria. Chlamydia infections are treatable and curable. However, its symptoms are often unnoticeable. It’s important to receive treatment for chlamydia as soon as possible. Chlamydia is caused by Chlamydia trachomatis (truh-KOH-muh-tis) bacteria and spread through oral, vaginal or anal sex. You might not know you have chlamydia because many people don't have symptoms, such as genital pain and discharge from the vagina or penis. Learn about chlamydia, including common symptoms in men and women, transmission risks, diagnostic testing, antibiotic treatments, and prevention. Chlamydial infection of the cervix (neck of the womb) is a sexually transmitted infection which has no symptoms for around 70% of women infected. The infection can be passed through vaginal, anal, oral, or manual sex.