If the thickening of the posterior wall of the uterus is detected by ultrasound, it may be caused by the following reasons: 1. adenomyoma of the uterus, which can cause local thickening of the posterior wall of the uterus, accompanied by increased menstrual flow, progressive aggravation of dysmenorrhea or infertility. 2. caused by local lesions of the uterus, mainly due to the presence of uterine sarcoma, which may also lead to thickening of the posterior wall of the uterus. 3. The first of these is to take a look at the results of the gynecological tumor examination, and then analyze the results. 3, the thickening of the posterior wall of the uterus may also be caused by fibroids, through the ultrasound examination can make the corresponding diagnosis, according to the results of the diagnosis and then intervention and treatment.