Chlamydia is a sexually transmitted infection (STI) that’s not always accompanied by symptoms. However, if left untreated, chlamydia can lead to serious complications. Find out about chlamydia, a sexually transmitted infection (STI), including symptoms, how it's treated, and how to prevent it. 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. 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 - A sexually transmitted disease that affects men & women. Learn more about the symptoms, diagnosis & treatment options. 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. This page answers basic questions about chlamydia, including how to prevent and treat it. 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 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. Chlamydia is spread through sexual contact. Symptoms may include a discharge from the penis or vagina and painful or more frequent urination. Special tests of a urine or vaginal sample can detect chlamydia. Antibiotics can cure the infections, and sex partners should be treated at the same time.