Menopause
Menopause is the time in middle age, usually in the late forties or early fifties, when a woman's menstrual periods cease completely. The average age at which women have their last period is 51. However, there is large variation in the age at which menopause occurs-from 39 to 59 years of age. Later menopause is linked with increased risk of breast cancer
In menopause, production of estrogen by the ovaries declines dramatically, and this decline produces uncomfortable symptoms in some women- "hot flashes," nausea, fatigue, and rapid heartbeat, for example. A recen study revealed that increased estradiol and improved sleep, but not hot flashes, predicted enhanced mood in women during their menopausal transition.