In men, it can spread to testicles and cause sterility. Chlamydia is diagnosed by examination of the cervix and applied laboratory culture or chemical tests of cells taken from the penis, cervix, urethra or anus. Gonorrhea Gonorrhea is a disease caused by bacteria called gonococci, contracted through sexual contact. Most women show no symptoms, according to Planned Parenthood. Gonorrhea causes serious infections in women's fallopian tubes which can lead to sterility.
Infected men have a thick yellow discharge, if they have symptoms at all.
Because gonorrhea might not produce symptoms, people must be tested for the disease. Herpes One in every six people have herpes, according to Planned Parenthood. Most people know herpes as the common cold sore, which is simplex one. Simplex two is genital herpes. Both simplexes are spread by direct skin contact.