Serum Creatinine Phosphokinase (CPK) Activity
This test measures the activity level of Creatine Phosphokinase, an enzyme found in heart, skeletal muscle, and brain tissues. It helps assess muscle damage or heart-related conditions.
["CPK helps identify muscle or heart injury by measuring enzyme release into blood after tissue damage."]
Key facts at a glance
- LOINC
- 9932-5
- Short code
- Q wave Dpth L-V2
- Synonyms
- Q wave Dpth L-V2
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- CPT
- 85610
- SNOMED
- 396252006
- 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 Is Creatine Phosphokinase (CPK)?
Creatine Phosphokinase (CPK), also called Creatine Kinase (CK), is an enzyme that plays a key role in energy production in cells. When muscle or heart tissue is damaged, CPK leaks into the bloodstream, raising its levels. This test helps doctors diagnose conditions like heart attacks, muscle injuries, or neurological disorders.
Why Might This Test Be Ordered?
Your doctor may order a CPK test if you have symptoms like chest pain, muscle weakness, or unexplained fatigue. It’s also used to monitor conditions such as heart attacks, muscle disorders, or to check for complications after surgery or trauma.
How Is the Test Performed?
A blood sample is taken from a vein in your arm. The sample is sent to a lab where the CPK enzyme activity is measured using an immunoassay or enzymatic method. Results are typically available within 24 hours.
What Do the Results Mean?
Elevated CPK levels may indicate muscle or heart damage, but they can also be influenced by factors like intense exercise, dehydration, or certain medications. Your doctor will interpret results in the context of your symptoms and medical history.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
CPK (Serum)
Frequently asked questions
How often do CPK levels naturally fluctuate?
What are the typical reference ranges for CPK?
Can CPK levels be affected by 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