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C-reactive protein (CRP) with plasma specimen, measured by nephelometry

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

This test measures the level of C-reactive protein (CRP) in your blood plasma, a protein produced by the liver that rises in response to inflammation or infection.

Quick summary

["CRP helps doctors assess inflammation, track infections, or monitor conditions like arthritis or heart disease."]

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

Key facts at a glance

LOINC
75680-9
Short code
Deprecated K oxytoca ompA Bld Pos Ql Prb Mag
Synonyms
Deprecated K oxytoca ompA Bld Pos Ql Prb Mag
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-mag-capture
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 doctor may order this test to check for signs of inflammation, monitor chronic conditions, or evaluate symptoms like fever, joint pain, or swelling. It can also help guide treatment decisions for infections or autoimmune diseases.

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

Higher CRP levels often indicate inflammation, but results alone don’t diagnose a condition. Your doctor will compare your results with your symptoms and other tests.

Common Conditions Monitored

This test is often used to monitor conditions like rheumatoid arthritis, heart disease, infections (e.g., pneumonia), or after surgery to check for healing progress.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker for systemic inflammation. Elevated levels may signal infections, autoimmune disorders, or tissue damage, but it’s not specific to any single condition. It’s often used alongside other tests for a full picture.

Short name

CRP Plasma (Nephelometry)

Frequently asked questions

Will I need to fast before this test?
No fasting is required for this test. However, if you’re on blood thinners or have a history of bleeding disorders, inform your healthcare provider before the test.
How long will it take to get my results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up.
Can I take anything before or after the test?
You can eat, drink, or take medications as usual. Avoid alcohol before the test if it affects your blood levels, but this doesn’t apply to CRP specifically.
  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