Under normal circumstances, the size and thickness of the uterus do not change, but the following conditions may cause changes in the size and thickness of the uterus: 1. After pregnancy, with the enlargement of the gestational sac and the growth of the fetus, the uterus will increase in size, which is a normal physiological state. 2. 3. In case of fibroids, the uterus will increase in size, and the initial diagnosis can be made by ultrasound examination. When the uterus is enlarged: 1) by physiological phenomena; 2) by pathological phenomena.