Chlamydia is a common sexually transmitted disease caused by bacteria. You get it by having sex or sexual contact with someone who is infected. Both men and women can get it. Chlamydia usually doesn't cause symptoms. If it does, you might notice a burning feeling when you urinate or abnormal discharge from your vagina or penis.
In both men and women, chlamydia can infect the urinary tract. In women, infection of the reproductive system can lead to pelvic inflammatory disease, which can cause infertility or serious problems with pregnancy. Babies born to infected mothers can get eye infections and pneumonia from chlamydia. In men, chlamydia can infect the epididymis, the tube that carries sperm. This can cause pain, fever and rarely, infertility.