What is this test?
CK is an enzyme released mainly from skeletal muscle, with smaller contributions from heart and brain. It rises after muscle injury, strenuous exercise and in some muscle disorders or medicine effects.
Why might it be ordered?
- To investigate muscle pain, weakness or suspected muscle injury.
- To monitor a medicine or condition that can damage muscle.
What sample is needed?
A blood sample is required. The laboratory chooses the correct tube and handles the sample for this test.
How should you prepare?
Avoid unusually strenuous exercise if your clinician agrees, and report injections, injury and medicines such as statins. Do not stop treatment on your own.
How should you understand the result?
The degree and trend matter, and muscle mass and activity affect the reference range. A marked rise with severe muscle pain or dark urine needs prompt medical review.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.