Tensing of the abdominal wall muscles to guard inflamed organs within the abdomen from the pain of pressure upon them. Abdominal guarding is detected when the abdomen is pressed and is an indication that inflammation of the inner abdominal (peritoneal) surface may be present due, for example, to appendicitis or diverti- culitis. The tensed muscles of the abdominal wall automatically go into spasm to keep the tender underlying tissues from being irritated.