exercise-induced hematuria

Etiology

• direct trauma to the kidneys &/or bladder
• contact sports
• long-distance running, less common with bicycling
• exercise may exacerbate hematuria in patients with underlying glomerular disease such as IgA nephropathy
• Nutcracker syndrome
  • compression of the left renal vein between the aorta & proximal superior mesenteric artery

Pathology

• generally glomerulonephropathy
  • renal ischemia due to shunting of blood to exercising muscles
  • lactic acidosis, generated during anaerobic conditions, causes passage of erythrocytes into the urine, through increased glomerular permeability
  • proteinuria often accompanies the hematuria
• ecchymoses & frank contusions have been noted on cystoscopy after long-distance running, possibly due to repeated impact of the flaccid wall of the bladder against the bladder base
  • a near empty bladder exacerbates the trauma

Clinical manifestations

• red to brown urine following exercise

Laboratory

• urinalysis
  • gross hematuria or microscopic hematuria

Diagnostic procedures

• cystoscopy in patients > 50 years of age

Differential diagnosis

• myoglobinuria due to rhabdomyolysis
• march hemoglobinuria

Management

• generally a benign condition

More general terms

• hematuria