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C-reactive protein (CRP) in serum/plasma

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

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in the body.

Quick summary

["CRP helps identify inflammation, often used to monitor conditions like infections or autoimmune diseases."]

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

Key facts at a glance

LOINC
109902-7
Short code
EBV VCA IgM Msmt CSF
Synonyms
EBV VCA IgM Msmt CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why might my doctor order a CRP blood test for me?

Doctors may order CRP testing to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. It can also help diagnose infections or assess risk for certain health issues.

What does it mean if my CRP test result comes back high?

Elevated CRP levels often indicate inflammation or infection. While not specific to a single condition, high levels may suggest conditions like rheumatoid arthritis, heart disease, or infections such as pneumonia.

What does it mean if my CRP test result comes back low?

Low CRP levels typically mean there is little to no inflammation present. However, very low levels might raise concerns if there’s an underlying condition requiring further investigation.

How is the CRP blood test performed, and what can I expect during the procedure?

A blood sample is taken from a vein, usually in your arm. The sample is then sent to a lab for analysis. The test measures CRP concentration in the serum or plasma.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP plays a key role in diagnosing and managing inflammatory diseases. It’s a useful marker for monitoring disease activity and guiding treatment decisions, though it’s not definitive on its own.

Short name

CRP

Frequently asked questions

How long does it take to get results?
Results are usually available within 1 to 3 business days, depending on your lab’s processing time.
Can I eat or drink before this test?
No special preparation is needed for this test. However, if your doctor has specific instructions, follow them.
Does this test require fasting?
No fasting is required for a CRP test, so you may eat and drink normally beforehand unless your doctor gives you different instructions.
  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