Menstrual pain is caused by cramps in a woman's lower abdomen which occur during, or just before, the start of her menstrual period. 

During her menstrual period, a woman's uterus contracts to help expel its lining. However, severe contractions triggered by hormone-like substances (prostaglandins) may constrict the blood cells feeding the uterus, resulting in pain. Higher levels of prostaglandins are associated with more severe menstrual cramps and more intense pain. Menstrual cramps may also be caused by specific, identifiable problems, such as endometriosis, uterine fibroids, adenomyosis, pelvic inflammatory disease (PID) or cervical stenosis.

Symptoms include throbbing or aching pains which can be dull or sharp, and range in severity from mildly annoying to so intensely painful they interfere with normal activities for a few days every month. Some women also experience headaches, nausea, dizziness and loose stools. Although menstrual pain may interfere with school, work and social activities, it doesn't cause any other medical complications. However, pain caused by an underlying condition may have associated complications such as fertility problems and ectopic pregnancies.

Menstrual cramps not caused by an underlying condition tend to lessen with age and often improve once a woman has given birth. Treatment for this type of pain includes nonsteroidal antiinflammatory drugs (NSAIDs) and hormonal birth control may also be administered in a variety of forms to prevent ovulation. When menstrual pain caused by an underlying disorder, treating this is key to reducing pain and in some cases, a physician may recommend surgery.