Uterine wall thickness means that the thickness of the uterine wall undergoes proliferation and is associated with the menstrual cycle, medications, and conditions such as endometritis and fibroids. Usually, uterine wall thickness means that the thickness of the uterine wall undergoes proliferative changes due to various reasons. Uterine wall thickness may be a normal physiological state related to the changes of the menstrual cycle, for example, on days 5-14 of the menstrual cycle under the action of estrogen, the endometrial surface shows proliferative changes, and the thickness of the endometrium proliferates from 0.5mm to 3-5mm. Secondly, if long-term exogenous intake of estrogen, such as oral contraceptive pills, taking estrogen supplementation therapy, to a certain extent, can also lead to cause uterine wall thickness. In addition to this, uterine wall thickening can also be caused by diseases such as endometritis, fibroids and adenomyosis.