Natural menopause or age-related cessation of normal regular menstrual cycles, is  determined when a woman has had no menstruation for at least 12 months. This is the result of depletion in ovarian follicles and associated estrogen deficiency. Menopause often occurs in women around the median age of 51 years.

Before menopause is perimenopause or irregular menstrual cycles, marked by hormonal fluctuations, hot flashes, sleep disturbances, mood symptoms, and vaginal dryness – and each individual will experience some or all of the these symptoms to a very variable degree. In addition to these, more changes begin to occur with lipids and bone density – both of which have implications for long-term health.

Early menopause, occurring between 40-45 years, and menopause occurring before age 40 years (so called Primary Ovarian Insufficiency) are both associated with excess risk for cardiovascular disease, bone loss and decline in cognitive functions.