A 22-Year-Old Football Player Who Collapsed Has Urine Changes

Faizah Siddique, MD; Herbert S. Diamond, MD


November 01, 2022


Rhabdomyolysis is extensive muscle injury. The muscle damage results in release of creatine kinase into the blood stream. Rhabdomyolysis symptoms can range from asymptomatic muscle enzyme elevation to acute kidney failure and muscle pain.

The rhabdomyolysis diagnosis in this patient was based on the marked elevation of creatine kinase levels and the dark urine that was positive for blood in the absence of red blood cells, along with his muscle pain and tenderness. The attribution to exercise with or without heat stroke is based on the history of vigorous exercise on a hot, humid day in a deconditioned and obese patient.

Intravascular hemolysis may produce dark urine that is positive for blood but not the marked elevation in creatine phosphokinase level, muscle pain, and tenderness. Genetic causes are unlikely, given the lack of prior episodes despite vigorous exercise. No evidence suggests sepsis.

Rhabdomyolysis has many causes, including the following[1,2]:

  • Trauma or muscle hypoxia, such as crush syndrome

  • Exertion related to strenuous or vigorous exercise especially with heat stroke

  • Genetic disorders

  • Infections primarily viral infection

  • Metabolic and electrolyte disturbances

  • Prescription medications, such as statins

  • Illicit drugs (eg, cocaine, heroin)

Trauma is the most common cause of rhabdomyolysis,[3] occurring in as many as 85% of patients with traumatic injuries. Between 10% and 50% of patients with rhabdomyolysis develop acute renal failure.[2,4] In critically ill patients, mortality can be as high as 59% with acute renal failure.[4,5]


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