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.
1 Chlamydia is one of the most common STDs. 2  Chlamydia is caused by a type of bacteria called Chlamydia trachomatis. 3  It can infect the urethra, rectum and eyes in men and women, as well as the cervix in women. 4  Chlamydia is spread via vaginal, anal or oral sex.