Under normal circumstances, the thickness of the endometrium of sexually mature women does not exceed 13 mm. No matter what age women are, if they develop an endometrial thickness of 20 mm, endometrial thickness of 20 mm is usually caused by endocrine diseases, endometritis, endometrial hyperplasia or polyps, endometrial cancer, etc. Therefore, if this situation occurs, they need to go to the hospital in time to identify the cause and Targeted treatment. Endometrial thickness of 20 mm is commonly seen in functional uterine bleeding during puberty or functional endometrial bleeding during menopause. Women in these two age groups are prone to luteal insufficiency due to unstable secretion of hormone levels in the body, and because of luteal insufficiency, it is easy for the endometrium to be continuously stimulated by estrogen without progesterone to counteract it, thus resulting in long-lasting hyperplasia, thus cause the endometrium to grow to a thickness of 20 mm. In addition, the possibility of endometrial cancer should be excluded if the endometrium is 20 mm thick. And it will lead to prolonged irregular vaginal bleeding, which needs to be treated by scraping and then sent to the hospital for pathological examination to rule out the possibility of endometrial cancer. Therefore, endometrial thickness of 20 mm is quite serious. For this condition, timely treatment is needed, listen to the arrangement of clinician, pay attention to rest and diet.