Pelvic inflammatory disease (PID) is an infection in the female reproductive organs and pelvis; which causes inflammation, scarring, pain, and infertility. In 90% of cases, PID is caused by chlamydia trachoma. Trachoma can also cause endometriosis, a painful condition in which the tissue lining the uterus grows outside the uterus. As trachoma spreads, it causes inflammation, scarring, inclusion cysts, and a sticky environment, which hampers the proper release of an egg from the ovaries, and implantation of a fertilized egg in the uterus.
Chlamydia trachoma can spread beyond the reproductive tract, to become systemic disease, including chronic urinary and kidney disease, autoimmune disease, connective tissue disease, joint disease, metabolic disease, central nervous system disease, eye disease and cancer.