Pelvic inflammatory disease (PID) is an infection of the uterus, fallopian tubes, or ovaries. If it isn't treated, PID can cause scar tissue in the fallopian tubes. This can lead to chronic pelvic pain, infertility, and other problems.

PID may not cause any symptoms. When it does, the most common symptom is pain in the lower belly. It's often described as cramping or a dull and constant ache. PID may also cause vaginal bleeding after sex, abnormal vaginal discharge, irregular menstrual bleeding, or a fever.

PID is usually treated with antibiotics. Any sex partners also need to be treated to avoid spreading the infection.

After you've had PID, you are more likely to get it again. PID is usually caused by a sexually transmitted infection (STI), such as gonorrhea or chlamydia. Taking steps to prevent STIs, such as using condoms, can help you avoid getting PID again.