Premenstrual Syndrome

Premenstrual syndrome (PMS) refers to the cyclic recurrence of certain physical, psychological, and behavioral symptoms that begin about a week before the menstrual period and disappear within a few days after menstruation starts.

Although American women commonly say that they have PMS or are “PMSing” anytime they notice a cyclic change, the term PMS should only be used to describe the experience of symptoms that are severe enough to interfere with a woman's daily life. According to the National Institutes of Health, symptom intensity must increase at least 30 percent in the six days before menstruation, and this pattern must occur for at least two consecutive menstrual cycles for the symptoms to be called PMS.

PMS symptoms vary from woman to woman, and even from one ...