Causes of Epididymitis
The cause of epididymitis is usually a bacterial infection. The bacteria usually get to the epididymis by moving back through (retrograde) the urethra, prostate, vas deferens into the epididymis. The responsible bacteria are usually identified in about 80% of cases.

Two main groups of organisms cause most cases of epididymitis: sexually transmitted organisms and coliforms (organisms that commonly live in the intestines).

In the conception of TCM, except for sexual transmitting, epididymitis is caused by obstruction of heat and dampness in pelvic cavity and obstruction of blood and Qi. Because of those obstruction, the organs in genital system is weaker than usual, the immunity is poorer, so the bacteria get a chance to infect the genital system.