Uterine distension is considered to be caused by physiological factors or may be caused by diseases. 1. Physiological factors: If uterine distension occurs before or during menstruation, it may be caused by PMS, which is a normal physiological phenomenon, and the symptoms usually disappear after the menstrual period is over. 2. Disease causes: endometritis, pelvic inflammatory disease and other diseases may cause the uterus to be stimulated, thus contraction, causing uterine distension. If this is the case, the patient should seek medical examination in time to clarify the cause of the disease and treat the symptoms. Any discomfort in the body should be taken seriously and prompt medical attention should be sought.