The hardness of the stomach may be related to abdominal muscle tension, constipation, peritonitis, tumor mass and so on. 1. Abdominal muscle tension: after coughing for a long time, engaging in heavy physical labor or exercising, the abdominal muscles will be more tense, and there will be hardness to the touch. 2. Constipation: Constipation usually occurs when too much food is consumed and too little exercise is done. As the fecal matter cannot be excreted, long, strip-shaped feces may be formed, and the abdomen may feel hard to the touch. 3. Peritonitis: patients with peritonitis may have abdominal muscle tension, abdominal pain, abdominal distension and other symptoms, resulting in a hard feeling on the stomach. 4. Tumor mass: Tumor mass can also lead to hardness of the stomach to touch, usually accompanied by a large range, hard texture, poor mobility and so on. There are many other reasons leading to the hardness of the stomach, it is recommended to go to the regular hospital in time, after clarifying the cause of the disease, under the guidance of the doctor to carry out targeted treatment.