At first, PID may not cause any symptoms or may cause only mild symptoms, such as abnormal bleeding or discharge from the vagina. Some women don't even know they have it. They only find out later, when they can't get pregnant or they have pelvic pain.
As the infection spreads, the most common symptom is pain in the lower belly. The pain has been described as crampy or as a dull and constant ache. It may be worse during sex, bowel movements, or when you urinate. Some women also experience fever and/or chills, nausea and/or vomiting, lower back pain, a feeling of fullness or bloating in the abdomen, and a general feeling of illness or tiredness.