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C-reactive protein (CRP) concentration, measured by nephelometry

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

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

Quick summary

["CRP helps doctors assess inflammation in your body."]

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

Key facts at a glance

LOINC
3271-4
Short code
LMWH PPP Chro-aCnc
Synonyms
LMWH PPP Chro-aCnc
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
chromo
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 Is This Test Done?

Your doctor may order this test to check for signs of inflammation, monitor conditions like rheumatoid arthritis, heart disease, or infections, or evaluate how well you’re responding to treatment for these conditions. It can also be used as a general health screening tool.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm, and a small amount of blood will be drawn. This is usually done in a lab or at a clinic.

What the Results Mean

Higher than expected levels may indicate inflammation, infection, or other health issues. Lower levels might suggest no active inflammation. Your doctor will discuss the results in the context of your overall health and medical history.

Common Conditions Monitored

Elevated CRP levels are often seen in conditions like infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., lupus, rheumatoid arthritis), heart disease, and some cancers. It can also be elevated due to stress, injury, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

Frequently asked questions

What causes CRP levels to be high?
CRP levels can rise due to infections, inflammatory diseases, injuries, surgeries, or certain medications. It may also be elevated during stress or illness. Your doctor will review your symptoms and medical history to determine the reason.
How long does it take to get CRP test results?
Results are typically available within a few days, depending on your lab’s processing times. Your doctor will contact you once they have the results.
Can diet or exercise affect CRP levels?
While diet and exercise can influence overall health and inflammation, they may not directly affect CRP levels. However, maintaining a healthy lifestyle can help manage conditions that might cause elevated CRP.
  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