CREATINE KINASE (CK- NAC), SERUM

Creatine Kinase (CK-NAC), Serum

What it is

The Creatine Kinase (CK-NAC), Serum test measures the total level of the enzyme creatine kinase (CK) in the blood using the NAC (N-acetylcysteine) activated method, which improves accuracy and stability of the enzyme measurement. CK is mainly found in skeletal muscles, heart muscle, and brain tissue. Elevated CK levels usually indicate muscle injury or stress on the heart or skeletal muscles.

Uses

This test is commonly used to detect muscle damage, evaluate suspected myocardial infarction (heart attack), and monitor conditions like muscular dystrophy, rhabdomyolysis, or inflammatory muscle diseases. It can also help track recovery after trauma, surgery, or intense exercise. When combined with CK isoenzyme tests (CK-MB, CK-MM, CK-BB), it provides more specific information about the source of damage.

Symptoms That May Lead to the Test

Your doctor may recommend this test if you experience chest pain, shortness of breath, muscle weakness, severe muscle pain, stiffness, swelling, dark-colored urine, seizures, or unexplained fatigue. It may also be ordered after accidents, strenuous exercise, or suspected drug-induced muscle injury (e.g., from statins).

Abnormal Results

High CK Levels: May indicate heart attack, skeletal muscle injury, rhabdomyolysis, muscular dystrophies, seizures, or inflammatory muscle conditions such as polymyositis. CK can also rise temporarily after heavy exercise or intramuscular injections.

Normal or Low CK Levels: Usually indicate no significant muscle or cardiac damage. Very low CK may sometimes be seen in reduced muscle mass or chronic illness.

Risks

The test involves a standard blood draw, with minimal risks such as mild pain, bruising, or dizziness at the puncture site. These side effects are temporary and uncommon.