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C-reactive protein (CRP) by nephelometry

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

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

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
16278-4
Short code
M tb DNA Bld Ql NAA+probe
Synonyms
M tb DNA Bld Ql NAA+probe
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
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 conditions like infections, autoimmune diseases, or heart disease, or evaluate responses to treatments that reduce inflammation.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm to draw blood. If you’re nervous, let your provider know—they can help make it more comfortable.

What the Results Mean

Higher CRP levels often indicate inflammation, but they can also be affected by other factors like fever, infection, or certain medications. Your provider will interpret results in the context of your overall health.

Common Conditions Monitored

This test is commonly used to monitor conditions like rheumatoid arthritis, lupus, heart attacks, or infections such as pneumonia or urinary tract infections.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

Frequently asked questions

Will this test hurt?
You might feel a slight pinch or discomfort when blood is drawn, but it usually lasts only a few seconds. Most people don’t experience lasting pain.
Can I eat or drink before this test?
You can eat and drink normally before this test unless your provider gives specific instructions. No fasting is required.
How long will I need to wait for my results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your provider 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