What is PMS?

Millions of women experience symptoms such as bloating, fatigue and breast tenderness during the days before their period. If these symptoms sound familiar, you could be suffering from premenstrual syndrome (PMS).

Premenstrual syndrome is a term used to describe a wide range of symptoms that might occur in the two weeks before a woman's menstrual period. These physical, emotional and behavioral symptoms usually stop when a woman's menstrual period begins, or shortly thereafter.

PMS can appear at any time between puberty and menopause. A woman's symptoms usually recur in a predictable pattern but may worsen with age or stress. It is also common for PMS to increase during times of hormonal instability, such as puberty, the time after childbirth and the period after a miscarriage or abortion. Changes in contraception may worsen PMS as well.

Most women experience some of the symptoms associated with PMS at some point in their lives, but not all women have the syndrome. While the exact number of women who have the condition is debatable, the National Institutes of Health estimates that 75 percent of menstruating women experience some form of PMS.

A smaller percentage (less than 10 percent) of women experience symptoms so severe it disrupts their daily lives. The more severe condition is called premenstrual dysphoric disorder (PMDD). Patients with PMDD are diagnosed under strict guidelines issued by the American College of Obstetricians and Gynecologists (ACOG). While the symptoms are similar, PMDD is considered a separate disorder from PMS.