Menopause occurs spontaneously around age 50 or at any age due to surgery, chemotherapy or some other contrived insult.

Natural menopause is unavoidable in the living, unless the ovaries are first surgically removed or become damaged & dysfunctional due to insults such as chemotherapy, diseases such as endometriosis or interference to the ovarian blood supply at hysterectomy. Pituitary failure is another cause. Artificial menopause is important because the hormonal changes occur earlier in life & are more severe than with natural menopause, leading to far greater mental & physical problems because of the premature loss of testosterone along with that of estradiol.