Peritonitis generally refers to a severe disease caused by bacterial infection, chemical irritation, or injury, most of which are secondary peritonitis originating from infections and necrosis of abdominal organs, perforations, trauma, etc. The main symptoms include abdominal pain, tense abdominal muscles, tenderness, and board-like abdomen. Pleurisy generally refers to the inflammation of the pleura caused by pathogenic microorganisms, also known as pleuritis, which can be accompanied by pleural effusion. Pleurisy is commonly caused by tuberculosis. Generally, the symptoms of peritonitis are more severe than those of pleurisy. Both pleurisy and peritonitis require active, timely, and regular treatment.