A painful period is often caused when the uterus contracts abnormally. This is because of a chemical problem in the body. For example, the natural chemical prostaglandin controls the contractions of the uterus.
When an underlying condition causes painful periods, it's often endometriosis. This is a condition where tissue from the lining of the uterus grows outside the uterus. Endometriosis often causes infertility and pelvic pain.
Other causes of painful periods include:
- Pelvic inflammatory disease (PID).
- Uterine fibroids.
- An abnormal pregnancy, such as a miscarriage or ectopic pregnancy.
- Infection, tumors, or polyps in the pelvic cavity.