Premenstrual Syndrome

Premenstrual syndrome (PMS) is a group of symptoms related to the menstrual cycle. PMS symptoms occur in the week or two weeks before your period (menstruation or monthly bleeding). The symptoms usually go away after your period starts. PMS may interfere with your normal activities at home, school, or work. Menopause, when monthly periods stop, brings an end to PMS.

The causes of PMS are not yet clear. Some women may be more sensitive than others to changing hormone levels during the menstrual cycle. Stress does not seem to cause PMS, but may make it worse. PMS can affect menstruating women of any age.

PMS often includes both physical and emotional symptoms. Diagnosis of PMS is usually based on your symptoms, when they occur, and how much they affect your life.

Estimates of the percentage of women affected by PMS vary widely. According to the American College of Obstetricians and Gynecologists, up to 40 percent of menstruating women report some symptoms of PMS. Most of these women have symptoms that are fairly mild and do not need treatment. Some women (perhaps five to ten percent of menstruating women) have a more severe form of PMS.