Source: Joseph Donroe, MD, Internal Medicine and Pediatrics, Yale School of Medicine, New Haven, CT

Abdominal pain is a frequent presenting concern in both the emergency department and the office setting. Acute abdominal pain is defined as pain lasting less than seven days, while an acute abdomen refers to the abrupt onset of severe abdominal pain with features suggesting a surgically intervenable process. The differential diagnosis of acute abdominal pain is broad; thus, clinicians must have a systematic method of examination guided by a careful history, remembering that pathology outside of the abdomen can also cause abdominal pain, including pulmonary, cardiac, rectal, and genital disorders.

Terminology for describing the location of abdominal tenderness includes the right and left upper and lower quadrants, and the epigastric, umbilical, and hypogastric regions (Figures 1, 2). Thorough examination requires an organized approach involving inspection, auscultation, percussion, and palpation, with each maneuver performed purposefully and with a clear mental representation of the anatomy. Rather than palpating randomly across the abdomen, begin palpating remotely from the site of tenderness, moving systematically toward the tender region, and thinking about what lies below the fingers at each position. A helpful technique is to imagine a clock face with the xiphoid process at 12:00 and the pubic symphysis at 6:00 (Figure 3). When palpating at 8:00, there is skin, muscle, cecum, appendix, and ureters. Performing the exam in this fashion assists in clinical reasoning and minimizes the chance of missing pathology.

Figure 1. Four abdominal quadrants. Abdomen can be divided into four regions by two imaginary lines intersecting at umbilicus. Right upper quadrant (often designated as RUQ), left upper quadrant (LUQ), right lower quadrant (RLQ), and left lower quadrant (LLQ) are shown.

Figure 2. Nine abdominal regions. Midclavicular lines and subcostal and intertubercular planes separate abdomen into nine regions: epigastric region, right hypochondriac region, left hypochondriac region, umbilical region, right lumbar region, left lumbar region, hypogastric region, right inguinal region, and left inguinal region.

Figure 3. Visualizing a clock face over the abdomen for thinking about the underlying anatomy while performing the exam.