Pelvic inflammatory disease (PID) is an infection of the female reproductive organs. It most often occurs when sexually transmitted bacteria spread from your vagina to your uterus, fallopian tubes or ovaries.

The signs and symptoms of pelvic inflammatory disease can be subtle or mild. Some women don’t experience any signs or symptoms. As a result, you might not realize you have it until you have trouble getting pregnant or you develop chronic pelvic pain.