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C-reactive protein (CRP) with plasma concentration measurement

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

This blood test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your 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
92970-3
Short code
K pneu grp DNA Spt NAA+non-prb-NCncRng
Synonyms
K pneu grp DNA Spt NAA+non-prb-NCncRng
Category
chemistry
Sample
sputum
Container
Sterile sputum container
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-probe-amp-tar
CPT
85610
SNOMED
396252006
Specimen volume
3-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions (such as arthritis or heart disease), or evaluate responses to treatments. It can also help diagnose infections or other inflammatory conditions.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader metabolic or liver evaluation. Bring any medications you’re taking to your appointment.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick. The blood sample is then sent to a lab for analysis.

What Do the Results Mean?

Results are interpreted based on your overall health and symptoms. Higher-than-normal levels may suggest inflammation, infection, or other health concerns. Your provider will discuss the results with you.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: sputum

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker for systemic inflammation. Elevated levels can indicate acute infections (e.g., pneumonia), chronic inflammatory diseases (e.g., rheumatoid arthritis), or conditions like heart disease. It’s often used alongside other tests to guide treatment decisions.

Short name

CRP Plasma

Frequently asked questions

How often should I get this test?
The frequency depends on your health condition. Some people get it every few months to monitor chronic inflammation, while others may need it only during illness or as part of routine check-ups. Follow your provider’s recommendations.
Does fasting affect CRP levels?
Fasting can slightly lower CRP levels in some people due to reduced inflammation from digestion. However, CRP is less affected by fasting than other tests like cholesterol. Your provider will clarify if fasting is required for this test.
Can I take anything before the blood draw?
Avoid heavy meals or alcohol 8–12 hours before the test if instructed. Otherwise, drink water and take your usual medications unless otherwise directed.
  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