Endometrial thickness of 20mm with uneven echogenicity may be caused by endocrine disorders, endometrial inflammation, endometrial polyps and so on. When endocrine disorders occur, the hormone levels in the body are disturbed and estrogen levels increase, which may lead to endometrial thickening. When endometrial inflammation, inflammation will stimulate the endometrial shedding, the endometrial shedding is incomplete, resulting in uneven echogenicity, and thickening of the endometrium. When endometrial hyperplasia causes polypoid changes in the endometrium, the ultrasound will show uneven echogenicity in the uterine cavity. If endometrial thickening and uneven echogenicity occurs, it should be evaluated in conjunction with the patient’s clinical symptoms, and there may be other causes, which require further hysteroscopy to confirm the diagnosis, and diagnostic curettage if necessary.