The main feature in recurrent myoglobinuria is frequent attacks of rhabdomyolysis accompanied by muscle pain and weakness, then myoglobin is excreted in the urine. These attacks are not related to exercise but they can be triggered by concomitant illnesses, such as upper respiratory tract infections. The disease usually has an early onset (less than 5 years of age) and can lead to renal failure.
Diagnosis is performed using physical examination of the muscles and biochemical tests to detect elevated plasma creatine kinase and myoglobinuria. During episodes, patients are treated with intravenous fluids and alkalinization to maintain normal plasma creatinine and urinary output. In between these episodes patients lead normal lives especially if excessive fasting is avoided.