Thin endometrium is usually caused by endocrine disorders, repeated abortions, uterine developmental abnormalities and so on. 1. Endocrine disorders: If endocrine disorders, manifested as abnormal secretion of hormones by the hypothalamic-pituitary-ovarian gonadal axis, lead to the endometrium not being able to proliferate normally, endometrial thinning may also occur. 2. Repeated abortions: Repeated abortions and scraping of the uterus can cause damage to the uterine lining, resulting in adhesions in the uterine cavity, leading to a thin uterine lining. 3. Abnormal development of the uterus: If the uterus develops in the shape of an elongated strip, instead of an inverted pear, this situation can also lead to a thin endometrium. Note that if the lining of the uterus is thin, you should go to the hospital for ultrasound, sex hormone six and other tests in time, and treat the problem in time.