There are many reasons why menstruation may be delayed in women in their 40s, including the decline of ovarian function. It may also be due to emotional or geographical influences, such as business trips or fatigue. It may also be caused by pregnancy due to lack of birth control. Therefore, if you experience delayed menstruation at this age, you should go to the hospital for a timely examination. Ultrasound examination of the uterine adnexa and the thickness of the endometrium, blood HCG test to rule out pregnancy, routine gynecological examination, cervical cancer screening and breast cancer screening should be performed. If there is no abnormal endometrial thickening, progesterone can be given orally twice a day at 100mg for 3-7 days, and menstruation will usually occur after 3-7 days of discontinuation.