Medical knowledge, Patient Education
Creatine Kinase Test
Why am I having this test?
The creatine kinase (CK) test is done to check for damage to muscle tissue in the body. When muscles are damaged, they release the enzyme CK into the bloodstream.
This test can be used to help diagnose a heart attack, muscle injury, or diseases of the skeletal muscles, brain, or spinal cord.
What is being tested?
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The total amount of CK in your blood (total CK).
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The amount of three different forms of CK (isoenzymes) in the blood:
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CK-MM, which is found in your skeletal muscles and heart.
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CK-MB, which is found mostly in your heart.
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CK-BB, which is found mostly in your brain.
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What kind of sample is taken?
At least one blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel. In some cases, you may need to have blood samples taken at regular intervals for up to 1 week.
Tell a health care provider about:
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All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
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Your activity level before the test. Your health care provider may ask you to avoid doing any exercise before the test, since muscle strain can temporarily elevate CK levels.
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Any bleeding problems you have.
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Any surgeries you have had.
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Any medical conditions you have.
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Whether you are pregnant or may be pregnant.
How are the results reported?
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How much total CK is in your blood, given as units per liter (units/L).
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How much of each measured isoenzyme is in your blood, given as a percentage.
Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference values). Reference values may vary among labs and hospitals.
For total CK, common reference values are ranges that vary by age, gender, race, and lab.
What do the results mean?
Results within reference ranges and values are normal. Levels of total CK that are higher than the reference ranges may mean that you have an injury or disease affecting your heart, skeletal muscles, or brain.
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Certain conditions affecting the skeletal muscle, such as:
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Rhabdomyolysis. This is a condition that can lead to breakdown of skeletal muscle.
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Duchenne muscular dystrophy (DMD). This is a condition that is passed from parent to child (is inherited). It can cause weakness and breakdown of skeletal muscle.
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A recent history of surgery or injury.
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Conditions that cause convulsions. These are episodes of uncontrollable movement caused by sudden, intense tightening (contraction) of the muscles.
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A recent history of heart attack.
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Other conditions that cause injury to the heart muscle.
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Taking certain psychiatric medicines.
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A disease that affects the brain and spinal cord (central nervous system).
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Certain types of cancer.
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Injury to the lungs.
Talk with your health care provider about what your results mean.
Questions to ask your health care provider
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When will my results be ready?
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How will I get my results?
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What are my treatment options?
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What other tests do I need?
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What are my next steps?
Summary
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The creatine kinase (CK) test is done to check for damage to muscle tissue in the body.
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This test can be used to help diagnose a heart attack, muscle injury, or diseases of the skeletal muscles, brain, or spinal cord.
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This test involves measuring total CK and three different forms of CK in the blood.
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Talk to your health care provider about what your results may mean.
This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.
