Premenstrual syndrome (PMS) (also called PMT or premenstrual tension) is a collection of physical, psychological, and emotional symptoms related to a woman's menstrual cycle. While most women of child-bearing age (up to 85%) report having experienced physical symptoms related to normal ovulatory function, such as bloating or breast tenderness, medical definitions of PMS are limited to a consistent pattern of emotional and physical symptoms occurring only during the luteal phase of the menstrual cycle that are of "sufficient severity to interfere with some aspects of life". These symptoms are usually predictable and occur regularly during the ten days prior to menses. Generally, symptoms may vanish either shortly before or after the start of menstrual flow.
Only a small percentage of women (2 to 5%) have significant premenstrual symptoms that are separate from the normal discomfort associated with menstruation in healthy women.
Culturally, the abbreviation PMS is widely understood in English-speaking countries to refer to difficulties associated with menses, and the abbreviation is used frequently even in casual and colloquial settings, without regard to medical rigor. In these contexts, the syndrome is rarely referred to without abbreviation, and the connotations of the reference are frequently more broad than the clinical definition.