Skip to content

Serum Creatinine Phosphokinase (CPK) Mass Concentration

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

This test measures the amount of Creatine Phosphokinase (CPK), an enzyme found in heart, muscle, and brain cells, in your serum. It helps assess muscle damage, heart injury, or other conditions affecting these tissues.

Quick summary

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

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

Key facts at a glance

LOINC
21034-4
Short code
11DC evening SerPl-mCnc
Synonyms
11DC evening SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Measure?

CPK is an enzyme that plays a 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 identify conditions like heart attacks, muscle injuries, or other illnesses affecting these organs.

Why Might You Need This Test?

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

When Will You Get Results?

Results are typically ready within 24 to 48 hours, depending on your lab’s processing time. Your doctor will discuss the findings with you during your follow-up visit.

What Are Common Causes of Abnormal Results?

Elevated CPK levels can occur due to muscle damage (e.g., from exercise, trauma, or conditions like myositis), heart problems (e.g., heart attack), or certain medications. Low levels may suggest muscle wasting or severe malnutrition.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CPK Serum

Frequently asked questions

Why do doctors check CPK levels?
Doctors check CPK levels to diagnose or monitor conditions affecting heart or muscle function. For example, high CPK can signal a heart attack or muscle injury, while low levels may require further investigation into underlying health issues.
What does a high CPK level mean?
A high CPK level often means your body is experiencing tissue damage, such as in a heart attack, severe muscle injury, or certain infections. Your doctor will review your symptoms and other test results to determine the cause.
How often should I get this test?
Your doctor will decide how often you need this test based on your health condition, symptoms, or treatment plan. Regular monitoring may be needed if you have a history of heart disease, muscle disorders, or other risk factors.
  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