Uterine thickening generally refers to thickening of the endometrium. Some patients may experience menstrual abnormalities such as heavy menstrual flow, prolonged menstrual periods, and amenorrhea, or they may not have any clinical symptoms. Some patients with endometrial thickening may not have any symptoms, while some may experience menstrual abnormalities such as irregular bleeding, excessive menstrual flow, prolonged menstrual periods, and amenorrhea. The thickness of the endometrium will be thinner, usually 3-5 millimeters, when the menstruation has just ended, but before the menstruation the endometrium is thicker, usually not more than 14 millimeters. So if the endometrium is slightly thickened before menstruation, but at the end of menstruation, it returns to normal, you can do without special treatment. When the above symptoms occur, you should consult a doctor to find out the cause and carry out targeted treatment.