Menopause
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
Menopause
During perimenopause, estrogen levels average about 20–30% higher than during premenopause, often with wide fluctuations. These fluctuations cause many of the physical changes during perimenopause as well as menopause, especially during the last 1–2 years of perimenopause (before menopause). Some of these changes are hot flashes, night sweats, difficulty sleeping, mood swings, vaginal dryness or atrophy, incontinence, osteoporosis, and heart disease. During this period, fertility diminishes but is not considered to reach zero until the official date of menopause. The official date is determined retroactively, once 12 months have passed after the last appearance of menstrual blood.