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C-reactive protein (CRP) by turbidimetry (high-sensitivity)

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

This test measures a protein in your blood that rises when your body is fighting inflammation, infection, or injury.

Quick summary

["High CRP levels may signal inflammation needing further evaluation."]

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

Key facts at a glance

LOINC
107364-2
Short code
FLUBV RNA Spt Ql NAA+n-prb
Synonyms
FLUBV RNA Spt Ql NAA+n-prb
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 doctor may order a high-sensitivity CRP test to check for signs of low-grade inflammation, monitor conditions like autoimmune diseases, or assess risk for heart disease or infections.

What Does the Result Mean?

Results are not given in specific numbers here, but doctors interpret them based on your overall health and symptoms. Elevated levels may prompt additional testing or treatments.

Common Conditions Monitored

This test is often used to monitor conditions such as rheumatoid arthritis, lupus, or other inflammatory diseases. It may also help track response to treatments.

Sample Collection

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum for testing.

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 of systemic inflammation. While not specific to any single condition, persistently elevated levels may indicate chronic inflammation or increased cardiovascular risk, guiding further diagnostic steps.

Short name

hs-CRP

Frequently asked questions

What causes CRP to be high?
CRP can rise due to infections (like colds or flu), injuries, surgeries, or certain medical conditions. It may also be elevated during pregnancy or with certain medications.
How soon after a problem might CRP levels change?
CRP levels can begin to rise within days of an injury or infection and may take weeks to return to normal. Your doctor will interpret results in context with your symptoms and other tests.
Can I eat or drink before this test?
Typically, fasting is not required for this test. However, always follow your doctor’s instructions, as some labs may have specific guidelines for your sample.
  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