A very hard stomach is considered to be caused by indigestion, intestinal obstruction, abdominal fluid accumulation, abdominal tumor and so on. 1. Indigestion: mainly after eating, the food stays in the gastrointestinal tract for a long time and produces a lot of gas, resulting in bloating and hardness of the stomach. 2. Intestinal obstruction: mostly caused by intestinal space-occupying lesions, such as intestinal tumors or intestinal adhesions, etc., which leads to the blockage of stool in the intestinal tract, and the pressure in the abdominal cavity increases, causing a hard stomach. 3. Abdominal fluid accumulation: such as hepatic ascites, venous obstruction, etc., which will lead to a large amount of fluid accumulation in the abdominal cavity, causing hardness of the stomach. 4. Abdominal tumors: including benign tumors or malignant tumors, with the gradual growth of tumor size, it will lead to obvious hardness in the abdomen. The hardness of the stomach may also be caused by other reasons. If the symptoms continue to be unrelieved, you should consult a doctor in time to find out the cause and then target treatment.