CREATINE PHOSPHOKINASE; CPK-NAC

What this test checks

Measures total CPK enzyme, which leaks out of injured muscle cells. High levels mean muscle injury, but the source could be heart, skeletal muscle, or even strenuous exercise.

Why do people get this test?

Used to investigate unexplained muscle weakness, muscle pain, or possible heart muscle damage.

When you should consider this test

• Muscle weakness or pain
• Suspected muscle disease
• Monitoring side effects of cholesterol medicines (statins)

How to prepare

Avoid strenuous exercise 24 hours before the test.