The lining of the uterus will continue to thicken after scraping, because the endometrium undergoes scraping surgery only to resolve the temporary thickening of the endometrium and to achieve the purpose of stopping bleeding. The cause of endometrial thickening is due to cyclic proliferation of the endometrium under the action of estrogen and endometrial exfoliation under the action of progesterone. Therefore, endometrial thickening is caused by hormonal dysfunction of the ovaries, and simple curettage cannot treat ovarian dysfunction, so the cause still exists. If there is no treatment after curettage, the ovaries still cannot ovulate normally, and the estrogen will not be able to strip the endometrium normally, and the endometrial thickening will occur again after 2-3 months.