43-year-old women suddenly do not have menstruation, mainly related to pregnancy, ovarian function decline, polycystic ovaries, ovarian cysts, patients should be clear cause after the treatment of the cause, as follows: 1, pregnancy: If the sudden appearance of non-menstruation after sex, may be due to pregnancy, patients can use early pregnancy test paper or blood test blood HCG value, can also do ultrasound to determine whether pregnancy, if clearly pregnant, normal 2. Ovarian function decline: With the decline of ovarian function, the level of estrogen and progesterone decreases, which can be manifested as the disappearance of menstruation, accompanied by anxiety, uncontrolled emotions, lack of concentration, sleep disorders, etc. Menopause is a normal natural phenomenon, but 43 years old is too early for menopause. Patients can do hormone replacement therapy under the guidance of physicians, and the symptoms can be relieved by regular exercise, balanced diet, quitting smoking and limiting alcohol, and keeping a happy spirit in daily life, while paying attention to the prevention of osteoporosis and avoiding fractures. Patients may experience menstrual irregularities, low menstrual flow or even amenorrhea, and may apply drugs such as dydrogesterone and progesterone to regulate the menstrual cycle; 4. ovarian cysts: cysts caused by abnormal proliferation of ovarian tissues may lead to menstrual irregularities with the enlargement of ovaries, and some patients may also experience abdominal pain and increased leucorrhea. Patients can undergo cyst removal under the guidance of a doctor to relieve symptoms.