The muscles in the stomach hurt when pressed in two ways, one is a problem with the muscles themselves and the other is a problem with the abdominal organs. The muscle problem is considered to be strain of the abdominal muscles after strenuous or improper exercise, and there is pain when pressing or contracting the abdominal muscles, such as turning over, sitting up and other movements. When lying down, resting, the abdominal muscle does not exert the pain, you can get gradual relief by applying heat and rest. If the pain is very severe even when lying still, it should be considered a problem of acute abdomen, such as appendicitis, cholecystitis, enteritis, etc. In this case the pain is not related to the position, and the curled up state will feel comfortable, once it is a problem of internal organs need to promptly go to the hospital.