Belly hard, there may be the following two reasons and the cause: 1, physiological reasons. People who often do abdominal muscle exercise, the abdominal muscles are thicker and stronger, there will be a hard feeling. Some of the more obese people, because of the stomach subcutaneous fat is more abundant, will also appear hard feeling. 2, may be the performance of peritonitis, common is the inflammatory stimulation of the abdominal cavity. For example, acute appendicitis, acute cholecystitis, pancreatitis or intestinal perforation, gastric perforation, etc., may stimulate the peritoneum leading to inflammation of the peritoneum, and there will also be abdominal muscle tension. If the pressure pain and rebound pain throughout the abdomen is severe, a platysmal abdomen may also occur.