Premenstrual syndrome is the term used for the physical and emotional symptoms that some women have before their menstrual period begins.
Symptoms range from mild to severe.
Severe symptoms may seriously disrupt daily life. PMS is related to hormonal changes during the menstrual cycle. A single cause of PMS has not been identified. Current research includes looking at the effects of a woman's cyclical hormones on brain chemistry and other aspects of body metabolism. The symptoms of PMS usually occur during the second half of the menstrual cycle.