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Serum Creatinine Phosphokinase (CPK) Isoenzyme Assay (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 muscle damage, heart function, or neurological conditions.

Quick summary

["CPK levels can signal muscle or heart injury; higher levels may indicate trauma, illness, or overuse."]

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

Key facts at a glance

LOINC
100846-5
Short code
DNV 1+2+3+4 nsP1 IgG SerPl Ql IA
Synonyms
DNV 1+2+3+4 nsP1 IgG SerPl Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 Does in Your Body

Creatine Phosphokinase (CPK) is an enzyme that helps produce energy in cells. When muscle or heart tissue is damaged, CPK leaks into the bloodstream, raising its levels. This test helps doctors identify sources of injury, such as a heart attack, muscle strain, or stroke.

Why This Test Might Be Ordered

Your doctor may order this test if you have symptoms like chest pain, muscle weakness, or unexplained fatigue. It’s also used to monitor conditions like heart disease, muscle disorders, or after injuries or surgeries.

Common Conditions Monitored

Elevated CPK levels often appear after muscle injuries (e.g., cramps, strains) or heart events (e.g., heart attacks). Low levels may suggest muscle wasting or certain metabolic disorders.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. Avoid intense exercise or strenuous activity 24 hours before testing if your doctor advises it.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total CPK

Frequently asked questions

Why might my CPK levels be checked?
Your doctor may check CPK levels to diagnose or monitor conditions like heart disease, muscle injuries, or neurological disorders. Elevated levels can indicate tissue damage, while low levels may warrant further investigation into metabolic or muscle-related issues.
What do my CPK results mean?
Results are compared to your baseline or lab reference ranges. Very high levels may signal acute injury, while persistently low levels could suggest chronic conditions like myopathy or thyroid dysfunction. Always discuss results with your healthcare provider.
Can CPK levels change with diet or exercise?
Yes, physical activity can temporarily raise CPK levels. Avoid intense exercise 24 hours before testing if your doctor recommends it. Dietary changes alone rarely affect CPK unless linked to muscle disorders like myositis.
  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