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
Removal of ovaries causes hormonal changes and symptoms similar to, but generally more severe than, menopause. Women who have had an oophorectomy are usually encouraged to take hormone replacement drugs to prevent other conditions often associated with menopause. Women younger than 45 who have had their ovaries removed face a mortality risk 170% higher than women who have retained their ovaries. Retaining the ovaries when a hysterectomy is performed is associated with better long-term survival. Hormone therapy for women with oophorectomies performed before age 45 improves the long-term outcome and all-cause mortality rates.