What is elevated creatine kinase? Creatine kinase or creatine phosphokinase 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. Creatine kinase is often incorrectly referred to as creatinine kinase. There are three different forms of creatine kinase that can be measured: CK-MM (located in the skeletal muscles and heart), CK-MB (mainly located in the heart), and CK-BB (located in the brain). An elevated level of creatine kinase, specifically CK-MB, occurs within hours of a heart attack as the heart muscle cells die. The enzyme level continues to rise for the first 18 to 24 hours after a heart attack and slowly returns to normal after a few days. If creatine kinase is elevated, a more specific test (troponin) can help confirm the presence of a heart attack. Trauma and other conditions that damage the skeletal muscle are also associated with an elevated creatine kinase level. In some cases the test may be used to detect muscle conditions such as polymyositis (condition characterized by the inflammation of muscles) or to estimate the degree of muscle damage. Stroke and other forms of brain damage can also result in an elevated creatine kinase level. An elevated creatine kinase can signal a heart attack or other emergency. Seek immediate medical care (call 911) if you, or someone you are with, have serious symptoms, such as chest pain or pressure and difficulty breathing accompanied by profuse sweating and rapid heart rate (tachycardia); or paralysis; sudden weakness or numbness on one side of the body; or confusion or loss of consciousness, even for a brief moment.