Natural menopause is the permanent ending of menstruation that is not brought on by any type of medical or surgical treatment. For women undergoing natural menopause, the process is gradual and is described in three stages:
Perimenopause. Perimenopause typically begins several years before menopause, when the ovaries gradually produce less estrogen. Perimenopause lasts up until menopause, the point when the ovaries stop releasing eggs. In the last one to two years of perimenopause, the decrease in estrogen accelerates. At this stage, many women experience menopause symptoms (see below).
Menopause. Menopause is the point when it's been a year since a woman last had her last menstrual period. At this stage, the ovaries have stopped releasing eggs and producing most of their estrogen.
Postmenopause. These are the years after menopause. During this stage, menopausal symptoms, such as hot flashes, ease for most women. However, health risks related to the loss of estrogen increase as the woman ages.