Serum Creatinine Phosphokinase (CPK) Activity
This test measures the activity of an enzyme called creatine phosphokinase (CPK), which helps assess muscle, heart, and brain health by detecting damage to these tissues.
["CPK levels can signal muscle injury, heart problems, or neurological conditions."]
Key facts at a glance
- LOINC
- 107442-6
- Short code
- XR UE XR 3D
- Synonyms
- XR UE XR 3D
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xr
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does CPK Measure?
CPK is an enzyme found in heart, skeletal muscles, and brain cells. When these tissues are damaged (e.g., from injury, illness, or overexertion), CPK leaks into the bloodstream, raising its levels. This test helps doctors identify sources of muscle or heart damage.
Why Is This Test Done?
Your doctor may order CPK testing if you have symptoms like muscle weakness, chest pain, shortness of breath, or unexplained fatigue. It’s also used to monitor conditions like heart attacks, muscle disorders, or nerve damage.
Common Reasons for Testing
Common reasons include suspected muscle injuries (e.g., from exercise, trauma), heart-related issues (e.g., after a heart attack or during heart surgery), or neurological conditions (e.g., stroke or seizures). It may also be checked during routine health evaluations or before certain procedures.
What to Expect Before the Test
No special preparation is needed, but avoid strenuous exercise or heavy lifting 24 hours before testing to get the most accurate results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CPK levels can indicate muscle or heart damage, helping diagnose conditions like myopathies (muscle diseases), heart attacks, or nerve disorders. High levels may prompt further testing for underlying causes.
Short name
CPK Serum
Frequently asked questions
How long does it take to get results?
What are normal CPK levels?
Can CPK levels change with diet or supplements?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy