Epididymitis is inflammation of the epididymis (the coiled tube on top of the testis that provides the space and environment for sperm to mature), and epididymo-orchitis is inflammation of the epididymis and testes.

Epididymitis and epididymo-orchitis are usually caused by a bacterial infection. Infection can result from surgery, the insertion of a catheter into the bladder, or the spread of infections from elsewhere in the urinary tract. Sometimes, particularly in young men, the cause is a sexually transmitted disease. Rare causes include infection by certain viruses or fungi. Sometimes there is no infection of any kind. In such cases, doctors believe the epididymis becomes inflamed by reverse flow of urine into the epididymis, perhaps because of straining (as when men lift something very heavy).

Symptoms of epididymitis and epididymo-orchitis include swelling and tenderness of the affected area, pain that may become constant and severe, fluid around the testes (hydrocele), and sometimes a fever. Rarely, an abscess (collection of pus) that feels like a soft lump develops in the scrotum.

Epididymitis and epididymo-orchitis are diagnosed by physical examination, urinalysis, and sometimes Doppler ultrasonography, which assesses blood flow to the testes. These disorders are usually treated with antibiotics taken by mouth, bed rest, pain relievers, and ice packs applied to the scrotum. Immobilizing the scrotum with a jockstrap decreases pain from repetitive, minor bumps. Abscesses usually require surgical drainage.

Last full review/revision October 2008 by Paul D. Lui, MD