The term premenstrual syndrome (PMS) refers to a constellation of mood and physical symptoms that occur during the luteal phase of the menstrual cycle. The National Association for Premenstrual Syndrome suggests that: ‘If PMS symptoms affect personal and/or social and/or professional quality of life then this should be regarded as being clinically significant PMS.’ Some women give a clear history of onset during the luteal phase of the menstrual cycle, with improvement taking place within a few days after the onset of menses. However, other women present with fluctuating symptoms without making a connection with their menstrual cycle. There are no diagnostic tests for PMS; diagnosis is dependent on the history.