This document provides information about Chlamydia, one of the most common sexually transmitted diseases. It can often cause no symptoms but can lead to further health issues if left untreated. Chlamydia is diagnosed via swab or urine tests and treated with antibiotics. Left untreated, it can cause complications like pelvic inflammatory disease and infertility in women or epididymitis and proctitis in men. Prevention methods include using condoms correctly, limiting partners, and getting tested and treated for any symptoms.