Primary amenorrhea is less common, mostly caused by genetic factors or congenital developmental abnormalities. The most common is secondary amenorrhea, the causes are very many, as follows: 1, common for stress amenorrhea, such as the patient suffered a mental blow, or someone in the family died, had a car accident, or environmental changes such as a change of place, resulting in hypothalamus inhibition, which leads to delayed menstruation and amenorrhea; 2, athletic amenorrhea, most often seen in athletes, will appear after sustained strenuous exercise, and if the body fat is reduced by 30% it will Amenorrhea, which is related to the stress response of the body; 3, amenorrhea caused by anorexia nervosa and excessive weight loss, in addition to amenorrhea, these patients also show extreme thinness, dry skin and lowered blood pressure, etc.; 4, organic amenorrhea, such as tumors of the hypothalamus and pituitary, endometrial tuberculosis destroying the endothelium, or excessive scraping caused by abortion, as well as postpartum purging damaging the endothelium, which leads to uterine cavity adhesions Or cervical tube adhesion and amenorrhea; 5, drug amenorrhea, such as patients taking psychotropic drugs, antidepressants, contraceptives will appear amenorrhea, but this amenorrhea in general after stopping most of the drugs can be restored; 6, premature ovarian failure caused by amenorrhea, if a woman before the age of 40 follicle exhaustion will be premature ovarian failure, and then the accompanying symptoms are usually referred to as menopausal symptoms, the same as the thyroid function problems. Problems with thyroid function can also cause amenorrhea.