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C-reactive protein (CRP) in plasma or serum, measured by nephelometry (CRP, high-sensitivity)

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

This test measures a protein produced by your liver in response to inflammation, helping detect low-level inflammation in your blood.

Quick summary

["A simple blood test to check for subtle signs of inflammation that may affect your health over time."]

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

Key facts at a glance

LOINC
92859-8
Short code
C pn + M pn DNA Pnl Lower resp NAA+probe
Synonyms
C pn + M pn DNA Pnl Lower resp NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 Is Done

Your doctor may order this test to monitor conditions like heart disease, autoimmune disorders, or infections where inflammation plays a role. It’s also used to check for early signs of inflammation after surgery or injury.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. If you’re nervous, let your healthcare provider know—you can ask for a numbing cream or distraction techniques.

What the Results Mean

Higher-than-normal levels may suggest inflammation, infection, or certain diseases. Lower-than-normal levels might indicate no active inflammation. Your doctor will compare your results to your health history and other tests.

Common Conditions Monitored

This test helps track conditions like coronary artery disease, rheumatoid arthritis, or inflammatory bowel disease. It’s also used in research or follow-up for people with chronic illnesses.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated CRP is a general marker of inflammation, often used alongside other tests to guide treatment decisions. It’s particularly useful for identifying subtle risks in people without obvious symptoms, such as early cardiovascular disease.

Short name

hs-CRP (high-sensitivity C-reactive protein)

Frequently asked questions

What does a high CRP level mean?
A high CRP level may indicate inflammation in your body, which can be caused by infections, injuries, or certain diseases. Your doctor will review your results with your full medical picture to determine next steps.
Can I eat or drink before this test?
You can eat and drink normally unless your doctor instructed otherwise. This test only requires a blood sample, so fasting isn’t needed.
How long will it take to get my results?
Results are typically available within 1–3 business days, depending on your lab. Your doctor will discuss them with you during your follow-up visit.
  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