When women in their late thirties or early forties begin to have symptoms of perimenopause such as hot flashes or vaginal dryness, they often wonder whether this is an early menopause. While the average age of menopause in the United States is 51, the usual range is from 45 to 55. If you completely stop having periods before the age of 45, it is called an early menopause. If you stop menstruating even earlier -- before the age of 40 -- it is called premature menopause. There are several reasons you might experience early menopause, including: Surgery to remove your ovaries.