In women of childbearing age, the first thing to consider in this case is the possibility of pregnancy. If pregnancy is not ruled out, then the condition may be due to mental stress, or environmental changes and excessive mental shock, resulting in abnormal secretion of pituitary gonadotropins. In some cases, the absence of menstruation may be due to abnormal secretion of lactogen in the body. In the case of menopausal women, ovarian failure and a decrease in the secretion of estrogen and progesterone by the ovaries may cause the absence of menstruation. Therefore, if you find that you are not menstruating, first of all, you should go to the hospital for a check-up and a urine test to rule out pregnancy; secondly, you need a blood test.