If an ultrasound shows an unusually thick endometrium, it mostly suggests that the patient has endometriosis, and the specific treatment depends on the cause of the endometriosis. Therefore, the patient should first have a hysteroscopy to determine the cause of endometrial thickening in general under hysteroscopic monitoring. If it is a polyp or submucosal fibroid, hysteroscopic electrodesiccation can be done and sent for pathological examination after electrodesiccation. If it is just endometrial thickening, there may be endometrial neoplastic lesions, which require diagnostic curettage under hysteroscopic monitoring, followed by pathological examination. If the result shown is only simple hyperplasia, oral progestin or the use of Mannitol can be used to inhibit endometrial hyperplasia and no special treatment is needed. In case of atypical hyperplasia or complex hyperplasia, or neoplastic lesions of the endometrium, the treatment plan needs to be determined according to the extent of the lesion, the presence or absence of fertility requirements, and the age of the patient. If the patient is of childbearing age, she can be treated with progesterone, or with the placement of Mannitol. If the patient is older and does not have fertility requirements, total hysterectomy or extended surgery can be done depending on the situation.