Definition of Premenstrual syndrome:

Premenstrual syndrome (PMS) refers to a wide range of physical or emotional symptoms that typically occur about 5 to 11 days before a woman starts her monthly menstrual cycle. The symptoms usually stop when menstruation begins, or shortly thereafter.

See also: Premenstrual dysphoric disorder (PMDD)

Causes, incidence, and risk factors:

An exact cause of PMS has not been identified. However, it may be related to social, cultural, biological, and psychological factors.

PMS is estimated to affect up to 75% of women during their childbearing years.

It occurs more often in women:

• Between their late 20s and early 40s
• Who have at least one child
• With a family history of a major depression
• With a history of postpartum depression or an affective mood disorder

The symptoms typically get worse in the late 30s and 40s as a woman approachs the transition to menopause.

As many as 50-60% of women with severe PMS have an underlying psychiatric disorder (premenstrual dysphoric disorder).