Menopause refers to a point in time that follows 1 year after the permanent cessation of menstrual periods that occurs naturally or is induced by surgery, chemotherapy or radiation. On average, natural menopause occurs between 50 and 51 years (range 45–59) and is part of the process of normal ageing. It has been noted that smoking advances the age of menopause by approximately 2 years. The diagnosis can only be made retrospectively and it is usually preceded by months or years of irregular cycles, that is not associated with some other physiological or pathological causes. If the cessation of menses occurs before the age of 40, then it is referred to as the "Premature ovarian failure". The older terms perimenopause or climacteric generally refer to the time period in the late reproductive years, usually late 40s to early 50s. Characteristically, it begins with menstrual cycle irregularity and extends to 1 year after permanent cessation of menses. The more correct t