Abdominal pain, either sudden or gradual in onset, frequently progresses in severity so that it becomes the dominant feature of the patient's illness. A careful and detailed history will define the time of onset of pain, its location, and whether a change in character occurs with various positions. Pain that persists for 6 hours or more, and is of severe intensity usually requires operative intervention for treatment of the underlying process. The exact situation in witch the onset of pain occurs may be important in establishing the diagnosis. Pain that is sharp, severe, and sudden in onset, awakening the patient from sleep or incapacitating the patient at work, often suggests a perforated viscus. Pain located in the upper abdomen favour peptic ulcer disease, acute cholecystitis, or pancreatitis, compared to ruptured ovarian cyst or perforated diverticulitis, when pain is located in the lower abdomen. The character of the pain initially and later is important in the differentiation of pain from small bowel obstruction or strangulation of the intestine. The former pain is a cramping, intermittent type of pain, whereas the latter causes a dull, constant pain. Sudden excruciating tearing pain may be associated with a ruptured aneurysm. Although in many cases the exact physical examination provide clues to the cause and determine whether urgent operation is indicated.