The diagnosis of a high-grade renal injury should be suspected in any patient after blunt trauma with one or more of the following findings: Microscopic hematuria with hypotension (systolic pressure < 90 mmHg) Gross hematuria Significant deceleration injury (eg, fall from a significant height, high-speed motor vehicle crash) Seat belt marks Diffuse abdominal tenderness Direct blow to the flank Lower rib or vertebral transverse process fractures Patients who are taking anticoagulants or who have a congenital renal anomaly can develop gross hematuria after relatively minor trauma.