What is the creatine kinase test?

This blood test measures an enzyme called creatine kinase (CK) or creatine phosphokinase (CPK). Enzymes are chemicals that help the cells of your body work. Muscle cells make the creatine kinase enzyme. When muscle cells are injured or diseased, enzymes leak out of the cells and enter the bloodstream.

This test is also called a total CK test.

Why is this test done?

The CK test may be done to check for muscle injury. It can give an idea of how bad the injury is, when it happened, and whether it is healing. Other blood tests may be needed to find which area has been injured.

The test may be done to:

• Diagnose the cause of chest pain, such as heart muscle damage from a heart attack
• Look for muscle injuries or diseases
• Check blood flow to the heart after heart surgery or other treatments that affect the heart muscle

How do I prepare for this test?

• If you are being checked for problems with your muscles, don’t exercise for 24 hours before the test.
• You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your healthcare provider knows about any medicines, herbs, or supplements that you are taking. Ask your provider before stopping any of your regular medicines.
• Talk to your healthcare provider if you have any questions about the test.

How is the test done?

Having this test will take just a few minutes. A small amount of blood is taken from a vein in your arm with a needle. The blood is collected in tubes and sent to a lab.

Ask your healthcare provider when and how you will get the result of your test.

What does the test result mean?

Some of the reasons your CK level may be higher than normal are:

• You have had a heart attack in the past 72 hours.
• You have over-exercised.
• You have recently had surgery.
• You have recently had a shot of medicine in one of your muscles.
• You have recently been in an accident or hurt one of your muscles.
• You have a muscle disease.

If your CK level is high, the test may be repeated as often as every 8 hours to see if the injury is healing or getting worse.

What if my test result is not normal?

Test results are only one part of a larger picture that takes into account your medical history, physical exam, and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the results and ask questions, such as:

• If you need more tests
• What kind of treatment you might need
• What lifestyle, diet, or other changes you might need to make