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. 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. Find out about chlamydia, a sexually transmitted infection (STI), including symptoms, how it's treated, and how to prevent it. To detect chlamydial infection, health care providers frequently rely on screening tests. Chlamydia is a common STD that can infect both men and women. It can cause serious, permanent damage to a woman’s reproductive system, making it difficult or impossible for her to get pregnant later on. Chlamydia - A sexually transmitted disease that affects men & women. Learn more about the symptoms, diagnosis & treatment options. 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. This page answers basic questions about chlamydia, including how to prevent and treat it. Chlamydia is a sexually transmitted infection (STI) that’s not always accompanied by symptoms. However, if left untreated, chlamydia can lead to serious complications. 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.