Soreness on both sides of the buttocks during menstruation may be related to sedentary activities and large changes in hormone levels. 1. Sedentary: women are usually tired and unwilling to move around during menstruation, which in turn leads to slower blood circulation due to prolonged sedentary behavior, making the two sides of the buttocks sore. 2. Large changes in hormone levels: During menstruation, relatively large changes in hormone levels in the body will cause the pelvis to become congested and edematous, which in turn affects the venous return of the inferior vena cava, resulting in pain and soreness on both sides of the buttocks. Soreness on both sides of the buttocks during menstruation may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.