The classical history in appendicitis is diffuse pain in the periumbilical region which then localizes as pain and tenderness at McBurney's point (associated with an inflamed appendix coming in contact with the surrounding parietal peritoneum). This point is located on the right-hand side of the abdomen one-third of the distance between the anterior superior iliac spine and the navel. Here, on gentle palpation, the abdominal muscles often feel firm to rigid because of involuntary spasm, and a cough also produces a localized soreness.