Chlamydia is a common sexually transmitted disease (STD) caused by the bacteria Chlamydia trachomatis. It can affect both men and women and is easily spread because it often causes no symptoms. Chlamydia can cause permanent damage to a womans reproductive system, leading to difficulties getting pregnant later, and can also cause a potentially fatal ectopic pregnancy. In men, chlamydia can cause a discharge from the penis, a burning sensation when peeing, and pain and swelling in one or both testicles (although this is less common) . Chlamydia can also infect the rectum in men and women, causing rectal pain, discharge, and bleeding. If left untreated, chlamydia can spread to the womb and cause a serious condition called pelvic inflammatory disease (PID), which is a major cause of ectopic pregnancy and infertility in women.

It is important to note that chlamydia can be asymptomatic, meaning that people can have the infection without showing any symptoms. Therefore, it is recommended that sexually active individuals get tested for chlamydia regularly, especially if they have multiple partners or do not consistently use condoms. Testing for chlamydia involves taking a sample of discharge from the penis or cervix, or a urine sample, which is then sent to a laboratory for analysis. Chlamydia can be treated with antibiotics, and both sexual partners must be treated to avoid passing the infection back and forth.