Endometrial thickening of 9mm can be caused by physiological reasons, there is no need for treatment; may also be caused by pathological reasons such as endocrine dysfunction, endometrial polyps and other diseases, hormone replacement therapy, surgical resection and other ways of treatment, need to be analyzed. 1. Physiological reasons: the endometrium will thicken before ovulation and menstruation, usually within 10mm, which is a normal physiological phenomenon and does not require treatment. 2. Pathological causes: if endometrial thickening occurs after excluding the above conditions, it may be pathological. If it is endocrine dysfunction, you can take hormone treatment; if it is endometrial polyp, you can take surgery to remove the treatment. There are other causes of endometrial thickening, such as endometrial cancer, which need to be treated according to different causes. Therefore, when endometrial thickening is detected, it is necessary to consult a doctor in a timely manner to clarify the cause of the disease and to target the treatment. Meanwhile, it is recommended that medication should be taken under the guidance of a doctor and should not be used without authorization.