Menarche is another name for the beginning of menstruation. In the United States, the average age a girl starts menstruating is 12. However, this does not mean that all girls start at the same age. A girl can begin menstruating anytime between the ages of 8 and 16. Menstruation will not occur until all parts of a girl's reproductive system have matured and are working together.
How long does a woman have periods? Women usually continue having periods until menopause. Menopause occurs around the age of 51, on average. Menopause means that a woman is no longer ovulating (producing eggs) and therefore can no longer become pregnant. Like menstruation, menopause can vary from woman to woman and may take several years to occur. Some women have early menopause because of surgery or other treatment, illness, or other reasons.
Next page: When Should I See a Health Care Provider About Period Problems? and How Often Should I Change Pads or Tampons?