Thick endometrium has a low chance of getting cancer and usually does not cause cancer. Thickening of endometrium is mostly seen in perimenopausal women. Due to the lack of progesterone in the body, estrogen in the body continues to stimulate endometrial proliferation, causing the endometrium to proliferate and thicken. Endometrial hyperplasia includes benign hyperplasia and atypical hyperplasia. Atypical endometrial hyperplasia has a certain possibility of cancer and requires diagnostic scraping, and if it is benign hyperplasia, it needs to be reviewed regularly to avoid cancer. If endometrial thickening occurs in women of childbearing age, it may be time for menstruation, and the thickening of the endometrium will resolve on its own after menstruation. Regardless of the reproductive age or perimenopause, endometrial thickening of more than 15mm is considered abnormal hyperplasia, and the cause needs to be identified and treated in the hospital.