Skip to content
FreeDoctor.org

Creatine Kinase Test

This test measures the amount of creatine kinase (CK) in your blood. High levels usually mean you have muscle damage, but the test cannot show where the damage is or what caused it.

What this test measures

This test measures the amount of creatine kinase (CK) in a sample of your blood. CK is an enzyme that helps make energy. Most CK is in your skeletal muscles, with smaller amounts in your heart and brain.

What your results mean

Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.

Higher-than-normal results

If your CK level is higher than normal, it usually means you have some type of muscle damage. High levels may be from skeletal muscle damage (CK-MM), heart muscle damage (CK-MB), or brain injury (CK-BB).

Frequently asked questions

What is creatine kinase (CK)?

CK is an enzyme that helps make energy in your body. Most of it is in your skeletal muscles, with smaller amounts in your heart and brain.

Why is a CK test done?

It is mainly used to help diagnose and monitor injuries and diseases that damage skeletal muscles, such as muscular dystrophy, rhabdomyolysis, and myositis. It may also be used for heart or brain conditions.

What does a high CK level mean?

A high CK level usually means you have some type of muscle damage. However, the test cannot show where the damage is or what caused it.

Can a CK test diagnose a heart attack?

A CK test may be used in some cases, but a troponin test is more often used because it is better at finding damage to the heart muscle from a heart attack.

What is a CK isoenzymes test?

This more specific test measures three types of CK (CK-MM, CK-MB, CK-BB) to help identify whether the damage is in your skeletal muscles, heart, or brain.

Related lab tests

Sources

Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.