What is it:
Menopause is the point in a woman’s life when menstruation stops permanently, signifying the end of her ability to have children. Known as the "change of life," menopause is the last stage of a gradual biological process in which the ovaries reduce their production of female sex hormones – a process which begins about 3 to 5 years before the final menstrual cycle. This transitional phase is called the climacteric, or perimenopause. Menopause is considered to be complete when a woman has been without periods for 1 year.
When does it occur:
Menopause generally occurs anywhere between the ages of 48 and 52. The average age of menopause is 50, however, it can occur as early as your late 30’s or as late as your mid-50’s. When menopause occurs before 35, it is technically considered to be premature menopause, but just as menarche is genetically predetermined, so is menopause. For most women, what they eat or do in terms of activity will not influence the timing of menopause. If a woman has had certain events in her medical history, such as chemotherapy or exposure to high levels of radiation, she might experience an earlier menopause. Women who have had mumps or some specific autoimmune diseases, such as lupus or rheumatoid arthritis, might also experience an earlier menopause. Smokers also tend to experience early menopause.
How does it happen:
The ovaries contain structures called follicles that hold egg cells. Women are born with about 2 million egg cells and by puberty there are about 300,000 left - only about 400 to 500 of these cells ever mature fully to be released during the menstrual cycle. The rest degenerate over the years. During the reproductive years, the pituitary gland in the brain generates hormones that cause a new egg to be released from its follicle each month. The follicle also increases production of the sex hormones – estrogen and progesterone. These hormones thicken the lining of the uterus and this enriched lining is prepared to receive and nourish a fertilized egg following conception. If fertilization does not occur, estrogen and progesterone levels drop, the lining of the uterus breaks down, and menstruation occurs.
For unknown reasons, the ovaries begin to decline in hormone production during the mid-30’s. In the late 40’s, the process accelerates and hormones fluctuate more, causing irregular menstrual cycles and unpredictable episodes of heavy bleeding. By the early to mid-50’s, periods finally end altogether.