Menopause is one point in a continuum of life stages for women and marks the end of their reproductive years. After menopause, a woman cannot become pregnant, except in rare cases when specialized fertility treatments are used. Most women experience menopause between the ages of 45 and 55 years as a natural part of biological ageing. Menopause is caused by the loss of ovarian follicular function and a decline in circulating blood oestrogen levels. The menopausal transition can be gradual, usually beginning with changes in the menstrual cycle. 'Perimenopause' refers to the period from when these signs are first observed and ends one year after the final menstrual period. Perimenopause can last several years and can affect physical, emotional, mental and social well-being. A variety of non-hormonal and hormonal interventions can help alleviate perimenopausal symptoms. Menopause can be a consequence of surgical or medical procedures.