At a Glance
Why Get Tested?
To find out if you have had a heart attack and if other muscles in your body have been damaged
When to Get Tested?
If you have chest pain or muscle pain and weakness
A blood sample taken from a vein in the arm
The Test Sample
What is being tested?
Creatine kinase is an enzyme found in the heart, brain, and skeletal muscle. Enzymes are proteins that help cells perform their normal functions. In muscle, for example, CK helps cells make the energy needed to move. CK occurs in three major forms, called isoenzymes:
- CK-MB (found mostly in your heart muscle),
- CK-BB (found mostly in your brain), and
- CK-MM (found in your heart and other muscles).
CK in the blood comes mainly from your muscles. The CK in your brain almost never gets into the blood.
How is the sample collected for testing?
A blood sample is taken by needle from the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Ask a Laboratory Scientist
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.