There is debate over the source of hematuria as well as the mechanism of bleeding in patients with exercise-induced hematuria. A renal (glomerular) origin has been supported by the finding of dysmorphic red blood cells on urinalysis[2]. Ischemic injury to the nephron and increased intraglomerular pressures have also been proposed[3]. "Nut-cracker syndrome" or aorto-mesenteric renal vein entrapment syndrome is another proposed mechanism. Compression of the left renal vein in the fork between the abdominal aorta and the proximal superior mesenteric artery result in left renal venous hypertension and development of collateral veins with intrarenal and perirenal varicosities. This leads to hematuria if the thin-walled septum separating the veins from the collecting system ruptures[4]. A lower urinary tract source of exercise-induced hematuria has also been proposed, which could be concomitant to an intrarenal source of bleeding. Bladder injury due to repeated impact of the posterior bladder wall against the bladder base has been postulated as a primary mechanism[5].
震動相對小的運動不容易出現運動後血尿，例如自行車運動，雖然不是沒有，但是很少。提示和震動有關。
