Creatine phosphokinase test

Creatine phosphokinase (CPK) is an enzyme in the body. It is found mainly in the heart, brain, and skeletal muscle. This article discusses the test to measure the amount of CPK in the blood.


How the Test is Performed


A blood sample is needed. This may be taken from a vein. The procedure is called venipuncture.

This test may be repeated over 2 or 3 days if you are a patient in the hospital.


How the Test will Feel


You may feel slight pain when the needle is inserted to draw blood. Some people feel only a prick or stinging sensation. Afterward, there may be some throbbing.


Why the Test is Performed


When the total CPK level is very high, it most often means there has been injury or stress to muscle tissue, the heart, or the brain. Muscle tissue injury is most likely. When a muscle is damaged, CPK leaks into the bloodstream. Finding which specific form of CPK is high helps determine which tissue has been damaged.

This test may be used to:

The pattern and timing of a rise or fall in CPK levels can be significant in making a diagnosis. This is particularly true if a heart attack is suspected.

In most cases, other tests are used instead of or with this test to diagnose a heart attack.


Normal Results


Total CPK normal values:

  • 10 to 120 micrograms per liter (mcg/L)

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.


What Abnormal Results Mean


High CPK levels may be seen in people who have:

  • Brain injury or stroke

  • Convulsions

  • Delirium tremens

  • Dermatomyositis or polymyositis

  • Electric shock

  • Heart attack

  • Inflammation of the heart muscle (myocarditis)

  • Lung tissue death (pulmonary infarction)

  • Muscular dystrophies

  • Myopathy

  • Rhabdomyolysis

  • Trauma

Other conditions that may give positive test results include: