Endometrial thickness of 18mm needs to be taken seriously and is usually indicative of a thick endometrium, which is an overgrowth of the endometrium. The thickness of the endometrium before menstruation is the thickest in a woman’s menstrual cycle, normally at 8-10 mm. endometrial thickness of 18 mm is divided into two main cases. If a woman is of childbearing age, there is a possibility of pregnancy. In this case, you can go to the hospital to check the blood HCG for determination. In addition, endometrial thickness of 18mm may also be caused by lesions of the endometrium, such as fibroids, endometrial polyps, etc., which are critical conditions. Patients can confirm the diagnosis in the hospital through hysteroscopy, etc., and take some medications to treat under the guidance of the doctor. If there is no improvement for a long time, scraping treatment may be needed, and also intrauterine banding with a Manned Ring can be used for treatment. Therefore women with endometrial thickness of 18mm should undergo further examination to clarify the exact cause. Women who are pregnant can take normal care. Women with endometrial lesions should take medication or other treatments as ordered by their doctors, relax and take care of their rest.