Although menstruation is often painless, many women suffer from discomfort or pain in association with periods at some time during their reproductive years. Primary dysmenorrhea frequently affects women in their teens and early 20s, who have never had a baby.
Severe pain occurs only in minority, but their is no doubt that it can be incapacitating.
The pain colicky in nature, usually starts on the first day of the period. It may last for several hours or continue throughout the first and second day. Often the menstrual flow is scanty at first, and then the pain becomes easier when the flow is properly established. The symptoms are caused by prostaglandin, a natural hormone produced by cells in the uterine lining. The level of prostaglandin increases in the second half of the menstrual cycle.