Myoglobinuria.

Myoglobinuria has a variety of causes, ranging from trauma to heavy exercise. Symptoms usually consist of myalgia and muscle weakness; dark, bloody-looking urine may be noted. Myoglobin can be identified by readily available laboratory techniques. Acute renal failure can be a dangerous consequence of myoglobinuria but, with rapid recognition and strict monitoring, the prognosis in most cases is good.