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C-reactive protein (CRP) in plasma by nephelometry

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 doctors assess inflammation, often used to monitor conditions like infections or autoimmune diseases."]

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

Key facts at a glance

LOINC
86234-2
Short code
N men sg A sacB Ct Spec Qn NAA+probe
Synonyms
N men sg A sacB Ct Spec Qn NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis or lupus, or evaluate symptoms such as fever, joint pain, or swelling that could indicate an infection or other health issue.

What to Expect Before the Test

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

What the Results Mean

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

Common Conditions Monitored

This test is often used to monitor conditions like infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., rheumatoid arthritis, lupus), or to check for signs of heart disease or other inflammatory processes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker of systemic inflammation. Elevated levels can signal acute infections, chronic inflammatory diseases, or conditions like heart disease, where inflammation plays a role. It’s not diagnostic alone but often used alongside other tests to guide treatment decisions.

Short name

CRP Plasma

Frequently asked questions

What causes CRP levels to rise?
CRP levels can increase due to infections (like colds or flu), injuries, surgeries, or certain medications. Chronic conditions like arthritis or heart disease may also lead to higher levels over time.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your provider will contact you with the results once they’re ready.
Can I eat or drink before this test?
You can eat and drink normally before this test, as it doesn’t require fasting. However, inform your provider if you’re on blood thinners or have any allergies to blood collection materials.
  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