Thin endometrium does not lead to any disease, but there are some diseases that cause thin endometrium. The main diseases are as follows: First, due to endocrine disorders and estrogen deficiency, the endometrium is too thin and clinically there can be reduced menstruation. Secondly, endometrial thinning due to endometrial tuberculosis. Thirdly, repeated abortions cause adhesions in the uterine cavity, which make the endometrium thin and clinically reduce menstruation or amenorrhea. Fourth, in case of polycystic ovary syndrome, it may also lead to thinning of the endometrium, scanty menstruation or amenorrhea. In addition, if ovarian function fails prematurely, it can also lead to thinning of the endometrium. So it is not the thinning of endometrium that causes certain diseases, but the thinning of endometrium caused by certain diseases, which must be checked and intervened as early as possible in clinical practice.