Epididymitis

Epididymitis is an infection or inflammation of the epididymis. The epididymis is a tube-shaped structure that sits behind and above the testicle. It's where sperm, the male reproductive cells, finish maturing before ejaculation, the moment they leave the body. Think of it as the room where they get ready before heading out.

Most of the time, the problem is bacteria that make their way into that room. In a sexually transmitted infection, bacteria get in during intercourse, meaning during sex, and travel through the genitourinary tract, the organs that handle both urine and reproduction, until they reach the epididymis. A urinary tract infection takes a different route: instead of moving out of the body, urine flows backward or sits still, and the epididymis ends up infected. Picture a drain where the water, instead of going down, backs up the pipe or just sits there: what was supposed to leave ends up somewhere it shouldn't be.

There's one more piece. The epididymis is so close to the testicle that the infection or inflammation can spread to the testicle itself. When that happens, the condition gets a new name: epididymo-orchitis.