Menopause
Menopause typically occurs between 49 and 52 years of age. The majority of women have their last period between the ages of 48 and 55. The average age of the last period in the United States is 51 years, in the United Kingdom is 52 years, in Ireland is 50 years and in Australia is 51 years. In India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. The menopausal transition or perimenopause leading up to menopause usually lasts 7 years (sometimes as long as 14 years).
Oophorectomy
Women who have had bilateral oophorectomy surgeries lose most of their ability to produce the hormones estrogen and progesterone, and lose about half of their ability to produce testosterone, and subsequently enter what is known as "surgical menopause" (as opposed to normal menopause, which occurs naturally in women as part of the aging process). In natural menopause the ovaries generally continue to produce low levels of hormones, especially androgens, long after menopause, which may explain why surgical menopause is generally accompanied by a more sudden and severe onset of symptoms than natural menopause, symptoms that may continue until the natural age of menopause. These symptoms are commonly addressed through hormone therapy, utilizing various forms of estrogen, testosterone, progesterone, or a combination.