Creatine Kinase

This test measures the amount of creatine kinase (CK) in a sample of your blood. CK is also called creatine phosphokinase (CPK). CK is an enzyme.

An enzyme is a protein that speeds up certain chemical reactions in your body. CK helps make energy. Most of the CK in your body is in your skeletal muscles.

These are the muscles you use to move. You also have CK in your heart muscle and small amounts in your brain. Normally, a small amount of CK gets into your blood from the usual wear and tear on your muscles.

But if your muscles, heart, or brain tissues are damaged, larger amounts of CK leak out of your cells into your bloodstream. A CK test is mainly used to help diagnose and monitor injuries and diseases that damage skeletal muscles and cause high levels of CK in your blood. But it may also be used for conditions that damage the heart muscle and the brain.

Why this test is done

You may need a CK test if you have symptoms of a muscular disorder. These include:

• Muscle pain and/or cramps
• Muscle weakness
• Balance problems and/or falling a lot
• Numbness or tingling
• Dark colored urine (pee)
• Swollen legs or feet

You may also need this test 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 to lower blood cholesterol
• Have had a stroke or traumatic brain injury (TBI)

How to prepare

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.

Sample type

Blood

Other names for this test

CK, total CK, creatine phosphokinase, CPK