Menstruation, periodic discharge from the vagina of blood, secretions, and disintegrating mucous membrane that had lined the uterus. 1  The biological significance of the process in humans can best be explained by reference to the reproductive function in other mammals.
Chlamydia is a common sexually transmitted disease (STD) caused by infection with Chlamydia trachomatis. It can cause cervicitis in women and urethritis and proctitis in both men and women.
Chlamydia, caused by the bacterium Chlamydia trachomatis, is currently believed to be the most prevalent bacterial STD in the United States. In men, the presence of the disease may be indicated by nonspecific urethritis, painful urination, and urethral discharge.