The CPK test is a laboratory test that measures the level of creatine phosphokinase (CPK) in the blood and is used to detect muscle damage in the body. CPK acts as a marker to diagnose problems such as heart attack, determine the cause of chest pain, neurological disorders, death of muscular tissue, convulsions and to give information about the muscular dystrophy status of a patient. Low CPK levels are indicative of acute viral hepatitis and alcoholic liver disease. Thus, a CPK blood test would help diagnose several medical conditions and helps in treatment before further damage is caused. A CK test may be ordered whenever muscle damage is suspected and at regular intervals to monitor for continued damage. It may be ordered when someone has experienced physical trauma, such as crushing injuries or extensive burns. The test may be ordered when a person has symptoms associated with muscle injury such as muscle pain or weakness and when a person has nonspecific symptoms, especially when taking a drug or after an exposure to a substance that has been linked with potential muscle damage. The CK test may sometimes be ordered when a person has chest pain and a heart attack is suspected. It may be ordered after a heart attack has been diagnosed to monitor for ongoing heart damage.