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Serum Creatinine Phosphokinase (CPK) Isoenzyme Analysis (Total CPK)

Published: August 9, 2026Updated: August 16, 2026

This test measures the total activity of Creatine Phosphokinase (CPK), an enzyme found in heart, muscle, and brain tissues. It helps assess damage to these tissues.

Quick summary

["CPK levels can indicate muscle, heart, or brain injury."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
18507-4
Short code
QRS axis HP RefB
Synonyms
QRS axis HP RefB
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ekg
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 CPK Total Measures

CPK is an enzyme that helps produce energy in cells. When tissues like the heart, muscles, or brain are damaged, CPK leaks into the bloodstream. This test checks the total CPK activity in your serum, which can signal where and how much damage has occurred.

Why This Test Might Be Ordered

Doctors may order this test to diagnose or monitor conditions such as heart attacks, muscle injuries (like from overexertion or trauma), or neurological issues. It can also help evaluate symptoms like chest pain, muscle weakness, or confusion.

Common Conditions Monitored

High CPK levels are often seen in conditions causing tissue damage, such as heart attacks, severe muscle injuries, or certain infections. Low levels may be normal or could indicate certain muscle disorders.

When to Expect Results

Results may take 1–3 business days, depending on your lab. Follow-up with your healthcare provider for interpretation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CPK Total

Frequently asked questions

What does a high CPK level mean?
A high CPK level suggests recent tissue damage, often in the heart, muscles, or brain. This could indicate conditions like a heart attack, muscle strain, or other injuries. Your doctor will discuss symptoms and other tests to determine the cause.
Can CPK levels be affected by diet or exercise?
Dietary factors like protein intake or alcohol may influence muscle enzymes, but CPK is most directly tied to tissue injury. Exercise can temporarily raise CPK levels, especially in athletes, but this usually returns to normal within days.
Is CPK the same as CK-MB (heart-specific CPK) or LDH?
No, CPK total includes all CPK isoenzymes (heart, muscle, brain). CK-MB is a specific heart-related CPK fraction, while LDH measures another enzyme group. Your doctor may order these separately for detailed evaluation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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