The common clinical causes of a hard belly include intestinal flatulence, peritonitis, and intra-abdominal masses. 1. Intestinal flatulence: this condition is also known as abdominal distension, which refers to the subjective feeling of abdominal fullness and increased intra-abdominal pressure or abdominal wall tension caused by excessive gastrointestinal gas. When the sick people in the clinic, the naked eye can see the abdominal bulging or abdominal circumference increase, press the feeling of abdominal hardness increase, serious clinical manifestations of abdominal pain, diarrhea, vomiting, constipation and so on. 2. Peritonitis: This disease refers to the inflammatory reaction of the abdominal cavity and peritoneum due to bacterial infection, chemical stimulation, physical injury and other factors. People with the disease have tense abdominal neuromuscular stimulation by inflammation, increased abdominal hardness on touch, accompanied by abdominal pain, nausea, vomiting, elevated body temperature and other symptoms. 3. Intra-abdominal mass: clinically, there are common peritoneal tumors, female uterine adnexal tumors, etc. Through CT and other imaging examinations, people with the disease can clearly identify the location of the mass and its general nature, and they can obviously feel that there is a hard substance in the abdominal cavity when they press on it during physical examination. In addition, there are tumors in the abdominal wall. In addition, patients with tumors in the abdominal wall and retroperitoneum can also cause abdominal hardness, and generally speaking, the cause can be clarified through CT magnetic resonance examination. If the symptoms persist or tend to worsen, it is recommended to go to the hospital and receive targeted treatment.