The first report of hematuria in runners appeared in these pages nearly 70 years ago.1 Since then, the subject has received more attention in locker rooms than in scientific journals. Now, with the current quest for physical fitness, physicians are encountering an increasing number of runners with grossly bloody urine. Failure to appreciate the nature of this disorder can lead to diagnostic confusion and inappropriate management.
Until lately, investigators believed that hematuria in runners stemmed from the kidneys. But, in 1976, at the American Medical Joggers' Association Fourth Annual Honolulu Symposium, my colleague and I presented circumstantial evidence incriminating the lower urinary tract as the site of blood loss. Our final report2 encompassed 13 men whose weekly mileage at the onset of gross hematuria ranged from 15 to 140 (24 to 224 km). Each runner had at least several bouts of frankly bloody urine, and two had countless