ETIOLOGY Y Diseases of the urinary system-the most common cause Vascular arteriovenous malformation arterial emboli or thrombosis arteriovenous fistular nutcracker syndrome renal vein thrombosis loin-pain hematuria syndrom cogulation abnormality excessive anticogulationETIOLOGY ✓ Diseases of the urinary system—the most common cause Vascular arteriovenous malformation arterial emboli or thrombosis arteriovenous fistular nutcracker syndrome renal vein thrombosis loin-pain hematuria syndrom cogulation abnormality excessive anticogulation