Creatine Kinase (Total CK)

Cardiac & Muscle

Normal Reference Ranges

Adult

Male: 55-170 | Female: 30-135 U/L

Pediatric

Varies by age and muscle mass U/L

Clinical Significance

Enzyme found heavily in skeletal muscle, heart, and brain. Extreme elevations (>5,000 U/L) strongly suggest rhabdomyolysis and risk of acute kidney injury.

Causes of High

  • Rhabdomyolysis
  • Myocardial Infarction
  • Muscular dystrophy
  • Severe exercise
  • Trauma/Crush injury
  • Statin myopathy

Causes of Low

  • Decreased muscle mass
  • Sedentary lifestyle