Menopause at 45 may be normal menopause, but it may also be abnormal menopause caused by pregnancy or polycystic ovary syndrome. 1. Menopause: If a woman has not had a period for 12 months, menopause at 45 may be normal menopause, which usually occurs naturally between the ages of 45-55. This is due to the fact that the ovaries are no longer secreting estrogen and are unable to stimulate the growth of the uterine lining, resulting in menopause. 2. Pregnancy: If a 45-year-old woman experiences menopause, but is also accompanied by nausea, vomiting and other symptoms of pregnancy, it is also necessary to consider whether it is caused by pregnancy, because 45-year-old women also have the probability of pregnancy. You need to go to the hospital to do blood HCG test to clarify whether pregnancy. 3. Polycystic ovary syndrome: patients with polycystic ovary syndrome have normal ovarian function, but ovulation will not occur, which will lead to the body’s estrogen and progesterone can not occur cyclical changes, so there will be a long time without menstruation symptoms. Normal menstruation may return after treatment. Women who have stopped menstruating at the age of 45 are advised to pay close attention to any other uncomfortable symptoms.