Epididymitis is swelling (inflammation) of the epididymis, the tube that connects the testicle with the vas deferens.

Epididymitis is most common in young men ages 19 - 35. It is a major cause of hospital admissions in the military.

Epididymitis is usually caused by the spread of an infection from the urethra or the bladder. The most common infections that cause this condition in young heterosexual men are gonorrhea and chlamydia. In children and older men,E. coli and similar infections are much more common. This is also true in homosexual men.

Mycobacterium tuberculosis (TB) can occur as epididymitis. Other bacteria (such as Ureaplasma) may also cause the condition.

Another cause of epididymitis is the use of a medication called amiodarone, which prevents abnormal heart rhythms.

The following increase the risk for epididymitis:

• Being uncircumcised
• Recent surgery or a history of structural problems in the urinary tract
• Regular use of a urethral catheter
• Sexual intercourse with more than one partner and not using condoms