Serum Creatinine Phosphokinase (CPK) or Serum Creatine Kinase (CK) Activity
This test measures the activity of creatine kinase, an enzyme found in heart, muscle, and brain cells. Elevated levels may indicate muscle damage or other conditions.
["CPK/CK helps identify muscle injury or related health concerns by tracking enzyme levels in your blood."]
Key facts at a glance
- LOINC
- 26703-9
- Short code
- ENA SM+RNP IgG Titr Ser IA
- Synonyms
- ENA SM+RNP IgG Titr Ser IA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 8
- Ref high
- 61
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- CPT
- 82977
- SNOMED
- 3110003
- 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
Why This Test Might Be Ordered
Your healthcare provider may order this test to diagnose or monitor conditions such as muscle injuries (e.g., from exercise, trauma, or overuse), heart-related issues (like a heart attack), or certain neurological disorders. It can also help assess muscle disorders or evaluate symptoms like weakness, pain, or fatigue.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid strenuous exercise or certain medications that could affect results. If you have a history of muscle damage or heart issues, inform your provider before the test.
What the Results Mean
Results are compared to a reference range for your age and sex. High levels may signal muscle injury, heart problems, or other conditions requiring further evaluation. Low levels might indicate normal muscle function or, rarely, certain metabolic disorders.
Common Conditions Linked to Abnormal Results
Elevated CPK/CK levels can be linked to conditions like muscle strains, heart attacks, seizures, or certain infections. Low levels are less common but may occur with certain genetic or metabolic disorders.
Reference range
Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CPK/CK is a critical marker for detecting muscle and cardiac damage. High levels often prompt further testing (e.g., ECG, additional blood tests) to determine the cause and guide treatment. It’s particularly useful in acute settings like diagnosing a heart attack or muscle injury.
Short name
CPK/CK Serum
Frequently asked questions
How long does it take to get my CPK/CK results?
Can I take anything before or after the test?
Does CPK/CK test require fasting?
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