What Is Premenstrual Syndrome?

The term premenstrual syndrome (PMS) refers to the physical and emotional symptoms that occur during the one or two weeks before the beginning of menstruation (the time in a woman's monthly cycle when she bleeds, also known as a woman's period). Sometimes PMS symptoms last a few days after menstrual bleeding starts.

PMS has been seen since the times of ancient Greece. It has been reported in Eastern (Asian) cultures as well as throughout the Western World. Modern scientific study of PMS has been going on since the early 1930s.

A woman is considered to have PMS when her premenstrual symptoms:

• cause significant discomfort

• interfere with her daily life

• occur primarily during the last two weeks of her menstrual cycle

• cannot be attributed to other conditions

At least 80% of menstruating women have some premenstrual symptoms:

• About 40% of menstruating women have PMS

• About 10% have severe symptoms, a condition called premenstrual dysphoric disorder (PMDD). Nine million women, or approximately five to seven percent of women of childbearing age, have PMDD.

For most women PMS symptoms are mild. In others, the symptoms may be severe and even incapacitating. The severity of a woman's symptoms has much more to do with her body chemistry than her personality.

PMS can occur at any time after puberty, but more women experience symptoms in their 30s and 40s than in their teenage years. Women who have had more children tend to have more severe symptoms, and women whose mother had PMS are at increased risk. PMS tends to get worse as women age and experience hormonal changes. Women with a history of depression have a greater risk of PMS.