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C-reactive protein (CRP) by nephelometry (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 your body.

Quick summary

["CRP helps identify and monitor inflammation, often used to check for infections, autoimmune conditions, or other health issues."]

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

Key facts at a glance

LOINC
82438-3
Short code
Deprecated ENA SS-B Ab CSF Ql IB
Synonyms
Deprecated ENA SS-B Ab CSF Ql IB
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
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 infections, autoimmune diseases, or heart disease, or evaluate responses to treatments. CRP levels can also help assess risk for certain health problems before symptoms appear.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results show how much CRP is in your blood. Higher levels often mean inflammation is present, but the exact meaning depends on your overall health and symptoms. Your doctor will interpret results in the context of your medical history.

Common Conditions Monitored

CRP is commonly used to monitor conditions like infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., rheumatoid arthritis), heart disease, and inflammatory bowel disease.

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 change?
CRP levels can rise due to infections, injuries, surgeries, or certain medications. They may also be higher in people with chronic conditions like heart disease or autoimmune disorders. Stress or recent illness can temporarily affect results.
How long does it take to get results?
Results are usually available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you with the final report.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management can influence CRP levels. Avoiding smoking and managing stress may also help lower inflammation.
  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