Creatine Kinase
Reviewed
Also called: CK test, total CK, creatine phosphokinase, CPK
This test measures the amount of creatine kinase (CK) in a sample of your blood. CK is also called creatine phosphokinase (CPK).
Specimen: blood
Why this test may be ordered
- To help diagnose and monitor muscle injuries, including injuries from accidents, serious burns, or extreme exercise.
- To help diagnose and monitor muscle diseases, including muscular dystrophy, rhabdomyolysis, and myositis.
- In certain cases, to help diagnose a heart attack (though a troponin test is used more often).
- If you have had a stroke, to find out how severe it was and help predict the chance of another stroke.
- If you have had an injury that crushed or tore your muscles, have had serious burns, take certain medicines that may cause muscle damage (such as statins), or have had a stroke or traumatic brain injury.
Preparation and collection
You don't need any special preparations for a CK test. To help make sure your results are accurate, your provider may ask you to avoid intense exercise and drinking alcohol for a few days before your test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Normal CK levels for you will depend on: Your age, sex, and race, How much muscle you have, How physically active you are
- Higher than normal CK level: If your CK level is higher than normal, it usually means you have some type of muscle damage. Limitation: But a CK test result can't show where the damage is or what's causing it. Next step: If the source of high or increasing CK levels isn't clear, you may need a more specific type of CK test to find out if the CK is coming from your muscles, heart, or brain.
- High or increasing on repeat tests: CK levels that stay high or increase may mean that muscle damage is continuing to happen. Limitation: CK levels may not reach their highest until up to two days after certain injuries. Next step: So, you may have more than one CK test to see if your levels go up or down.
- A CK test result cannot show where the damage is or what is causing it.
- CK levels may not reach their highest until up to two days after certain injuries, so you may need more than one test to see if your levels go up or down.
- To diagnose the condition causing high CK levels, you may need other types of tests.
What to do next
If you have questions about any of your test results or diagnosis, talk with your provider.
- What do my CK test results mean in relation to my symptoms and medical history?
- Do I need a CK isoenzymes test or other follow-up tests?
- What is the likely cause of any muscle damage indicated by my results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.