Premenstrual syndrome (PMS) can usefully be defined as ‘a condition manifesting with physical, behavioural and psychological symptoms in the absence of organic or psychiatric disease, which regularly occurs during the luteal phase of each ovarian cycle and which disappears or significantly regresses by the end of menstruation’. PMS is considered severe if it impairs work, relationships or usual activities. Some observers note that as many as 95% of women suffer mild symptoms, and between 5% and 10% of women have symptoms severe enough to disrupt their lives, principally in the 2 weeks leading up to the start of menstruation.

Over 150 symptoms have been attributed to PMS, but particularly:

 mood changes/irritability

 abdominal bloatedness

 breast tenderness (cyclical mastalgia)

 headaches

 oedema.

The aetiology of PMS remains largely unknown. Ovulatory cycles are generally considered to be a necessary prerequisite. Many hypotheses have considered whether there might be abnormal levels of specific hormones, and research has focused on progesterone, oestrogen, adrenocorticotrophic hormone, vasopressin, luteinizing hormone, prolactin and thyroid-stimulating hormone. There is no consistent evidence that any of these are abnormal in PMS, but there are suggestions that it is the changing patterns of hormone levels, rather than the absolute levels, which is important. There may be an abnormality in levels of neurotransmitter function, particularly serotonin, and this is discussed further under ‘Management’, below.