Kehr's sign

A sharp pain referred to the left shoulder caused by blood irritating the diaphragm. In the trauma patient, Kehr's sign strongly suggests splenic injury. Diaphragmatic irritation by free blood stimulates the phrenic nerve, and the brain interprets this as left shoulder pain. Occasionally, Kehr's sign occurs on the right side in patients with hepatic injury. Other Kehr's sign etiologies include ruptured ectopic pregnancy and renal calculi.