Creatine kinase (CK) is an enzyme chiefly found in the brain, skeletal muscles, and heart. An elevated level of creatine kinase is seen in heart attacks, when the heart muscle is damaged, or in conditions that produce damage to the skeletal muscles or brain.
The level of Creatine Kinase in the blood is measured to assess muscle damage – it can rise very quickly after muscle trauma, but will begin to lower as the damage is repaired. If Creatine Kinase continues to rise it indicates that muscle damage is not being repaired.