Menopause
Menopause is the natural and permanent stopping of menstruation. Female hormone levels change, since they were produced by the ovaries which have stopped ovulating. The female can no longer have children after this happens. The menopausal transition most often begins between ages 45 and 55. The duration can depend on lifestyle factors such as smoking, age it begins, and race and ethnicity. During perimenopause, the body's production of estrogen and progesterone, two hormones made by the ovaries, varies greatly.