P.I.D. stands for pelvic inflammatory disease. This is an infection of the female reproductive organs, including the uterus, fallopian tubes, and ovaries. It is usually caused by sexually transmitted infections, such as chlamydia or gonorrhea, but can also result from other types of bacteria. P.I.D. can cause symptoms like pelvic pain, abnormal vaginal discharge, painful urination, and fever. If left untreated, it can lead to complications like infertility or chronic pelvic pain. Therefore, it is important to diagnose and treat P.I.D. promptly to prevent long-term complications.