Creatine Kinase (CK)

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Latest Edit: Hector 2014-03-24 (EDT)

See Also Lab Tests

This test is used to detect myocardial muscle injury or infarction. It can also useful in detecting neurologic or skeletal muscle diseases.[1], [2]


  • CK is predominantly found in the heart muscle, skeletal muscle, and brain.
  • Serum CK levels are found to be elevated when these muscle or nerve cells are injured and rise within 6 hours after damage.
  • Three CK isoenzymes that are used specifically for myocardial muscle injury are CK-BB (CK1), CK-MB (CK2), and CK-MM (CK3); the CK-BB isoenzyme is found predominantly in the brain and lung, causing elevated levels of the isoenzyme with injury to any of these organs. The CK-MB isoenzyme portion are specific for myocardial cells and is helpful in quantifying both the degree of mycardial infarction (MI) and timing the onset of infarction. The CK-MM isoenzyme is composed of almost all of the circulatory total CK enzymes in healthy people.

Patient Preparation

  • No food or fluid restrictions are required.
  • Factors which can cause increased levels:
  • IM injections, strenuous exercise, recent surgery
  • Factors which can cause decreased levels:
  • Early pregnancy

Clinical Implications

High levels indicate:

  • For total CK:
  • diseases or injury affecting the heart muscle, skeletal muscle, and brain
  • For CK-BB isoenzyme:
  • Diseases that affect the central nervous system (CNS)
  • Electroconvulsive therapy
  • Adenocarcinoma (especially breast and lung)
  • Pulmonary infarction
  • For CK-MB isoenzyme:
  • AMI
  • Cardiac aneurysm surgery
  • Cardiac defibrillation
  • Myocarditis
  • Ventricular arrhythmias
  • Cardiac ischemia
  • For CK-MM isoenzyme:
  • Rhabdomyolysis
  • Muscular dystrophy
  • Myotis
  • Recent surgery
  • Electromyography
  • IM injections
  • Trauma
  • Crush injuries
  • Delirium tremens
  • Malignant hyperthermia
  • Recent convulsions
  • Electroconvulsive therapy
  • Shock
  • Hypokalemia
  • Hypothyroidism

Associated Tests


  1. Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
  2. Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.