Appendicitis is common, with a lifetime occurrence of 7 percent. Abdominal pain and anorexia are the predominant symptoms. The most important physical examination finding is right lower quadrant tenderness to palpation. A complete blood count and urinalysis are sometimes helpful in determining the diagnosis and supporting the presence or absence of appendicitis, while appendiceal computed tomographic scans and ultrasonography can be helpful in equivocal cases. Delay in diagnosing appendicitis increases the risk of perforation and complications. Complication and mortality rates are much higher in children and the elderly.