Exertional hematuria: definition, epidemiology, diagnostic and clinical considerations

Abstract

Exertional hematuria can be considered a subcategory of exercise-induced hematuria, characterized by painless appearance of erythrocytes in urine after recent physical exercise, not directly attributable to external traumatic injuries to the genitourinary system, and spontaneously resolving with rest. Although its frequency has enormous heterogeneity, depending on the athlete population, duration and intensity of exercise, technique used for identifying or quantifying hematuria and relative diagnostic thresholds, what clearly emerges from the scientific literature is that a certain degree of hematuria is commonplace after non-contact sports, especially running. This exertional hematuria, which appears self-limiting, may be attributable to some frequently concomitant causes, involving organs of the genitourinary system, and mostly encompassing bladder or urethral injuries. Renal injuries caused by internal movements, vascular spasm and ischemia are also potential causes of increased glomerular permeability to erythrocytes, whilst the presence of preexisting genitourinary diseases cannot be ruled out, especially when post-exercise hematuria is recurrent or endures. Therefore, whenever hematuria is observed in a random urine specimen, recent sports performance (especially running) should be investigated and urinalyses scheduled for the following days. When no temporal association of hematuria with exercise can be found, when genitourinary traumas have been excluded or hematuria persists for >72 h, specific diagnostic investigations should be planned to identify possible genitourinary diseases.

Effects of Monomeric and Oligomeric Flavanols on Kidney Function, Inflammation and Oxidative Stress in Runners: A Randomized Double-Blind Pilot Study

“…The appearance of blood in the urine after strenuous exercise reveals an increased glomerular permeability to erythrocytes. Several mechanisms have been postulated to be involved in this phenomenon, including vascular spasms, ischemia, endothelial dysfunction and oxidative stress [ 50 ]. The investigated MOF-VVPP appears to act on both the tubular and glomerular sites of possibly exercise-related alterations in the kidney functions.…”

Retrospective analysis of 116 cases of exertional rhabdomyolysis in newly enrolled cadets of a military academy in Beijing

“…Myalgia and darkened urine were the two main symptoms of ER. Especially when urine turned brown or even darker, the possibility of ER increased by 18 times (Table 2), indicating the occurrence of myoglobinuria; but the possibility of exercise-induced hematuria cannot be ruled out in practice [8] .…”

Exertional hemolysis and hematuria in a Labrador Retriever dog

“…It is described as mild, self-limiting RBC destruction following exercise of variable intensity. 16 A combination of mechanical 21 , 27 and metabolic 4 , 29 insults to erythrocytes during exercise is suspected to exacerbate their fragility, leading to hemolysis. Limited data exist in the veterinary literature regarding exertional hemolysis.…”

“…RBC compression within the muscular capillary beds during powerful contractions may also contribute to hemolysis. 16 Metabolic stressors associated with exercise, including dehydration, 22 lactic acidosis, 14 hyperthermia, 20 increased catecholamine concentrations, 28 regional hypoxia, 18 and oxidative damage 26 among others, are suspected to promote osmotic fragility and alter the RBC membrane structure and deformability, increasing the likelihood of hemolysis.…”

“…Exertional hematuria was first reported in people in 1910 and was later defined as microscopic and macroscopic hematuria developing after a session of strenuous exercise in subjects without evidence of kidney or other urinary tract disease that resolves with rest, typically within 2–72 h following exercise. 2 , 12 , 16 The exact mechanism of hematuria following exercise is not understood completely. A component of internal trauma to the urinary tract is suspected, as witnessed by the presence of hemorrhage at the bladder neck and posterior urethra in human male runners secondary to repeated impact, particularly if strenuous exercise is undertaken with an empty urinary bladder.…”