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C-reactive protein (CRP) by nephelometry (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 doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
94628-5
Short code
Mp bovis DNA Ct Spec Qn NAA+probe
Synonyms
Mp bovis DNA 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 doctor may order CRP testing to check for signs of inflammation, monitor chronic conditions (such as rheumatoid arthritis or heart disease), or evaluate responses to treatments. It can also help identify infections or other inflammatory processes in your body.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm to draw blood. If you’re concerned about blood draws, let your healthcare provider know.

What the Results Mean

Higher-than-normal CRP levels often indicate inflammation, but they can also be influenced by factors like fever, infection, or certain medications. Your doctor will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

CRP is commonly used to monitor conditions like infections (e.g., pneumonia), autoimmune diseases (e.g., lupus), heart disease, or to check healing progress after surgery or injury.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker of systemic inflammation. While not specific to a single condition, elevated levels often prompt further investigation into possible infections, autoimmune activity, or other inflammatory processes. It’s a useful tool for guiding treatment decisions and monitoring disease activity.

Short name

CRP Plasma

Frequently asked questions

What causes CRP levels to rise?
CRP levels can increase due to infections (like a cold or urinary tract infection), injuries, surgeries, autoimmune diseases (such as rheumatoid arthritis), or other inflammatory conditions. Stress, certain medications, or even pregnancy may also affect CRP levels.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will contact you once they have the results.
Can diet or lifestyle affect CRP levels?
Yes, diet, exercise, and overall health can influence CRP levels. Reducing processed foods, increasing omega-3 fatty acids (found in fish), and maintaining a healthy weight may help lower inflammation. Always discuss lifestyle changes with your doctor before making significant adjustments.
  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