There are more reasons why the stomach is hard when pressed, and the common ones are digestive system diseases, general surgery diseases and urology diseases. 1. Digestive system diseases: for example, acute gastroenteritis, there may be abdominal pain when pressing, hardness when pressing the abdomen, but the pain is not obvious, as well as acute gastrointestinal perforation, which will also have such a phenomenon, but there will be obvious pressing pain. 2. General surgical diseases: including acute appendicitis perforation, acute intestinal obstruction, acute diffuse peritonitis, etc., are prone to this symptom, which is also known as plate-like abdomen. 3. Urological diseases: for example, ureteral stones, kidney stones, etc., resulting in ureteral stenosis, when the abdomen is pressed, it is also prone to hardness, and is accompanied by the symptom of lumbar pain. The hardness of the stomach when pressed may also be abdominal tumor occupation, it is recommended that the patient go to the hospital in time, through the improvement of various examinations, clear diagnosis, and then carry out active treatment.