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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, a protein produced by the liver in response to inflammation in your body. It helps doctors assess whether you have an inflammatory condition or infection.

Quick summary

["CRP helps track inflammation, guiding treatment decisions and monitoring recovery."]

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

Key facts at a glance

LOINC
72391-6
Short code
C tropicls DNA Vag Ql NAA+probe
Synonyms
C tropicls DNA Vag Ql 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 CRP Matters in Your Health

CRP is a marker of inflammation, which can occur due to infections, injuries, autoimmune diseases, or other conditions. High CRP levels may signal an active inflammatory process, prompting further evaluation or treatment adjustments.

How the Test Works

Your blood sample is analyzed using nephelometry, a method that detects the protein’s presence by measuring light scattering. This helps determine how much CRP is circulating in your blood.

Common Uses for CRP Testing

Doctors may order CRP tests to monitor chronic conditions like rheumatoid arthritis or heart disease, evaluate symptoms of infections (e.g., pneumonia, appendicitis), or assess response to treatments.

What to Expect Before the Test

No special preparation is needed. A simple blood draw is all that’s required. If you’re on blood thinners or have a history of bleeding disorders, let your provider know.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

Frequently asked questions

CRP is often used alongside other tests to diagnose or monitor conditions like infections, autoimmune diseases, or cardiovascular risks. While not definitive on its own, it provides critical context for clinical decisions.
CRP results are typically compared to your baseline or clinical picture rather than absolute reference ranges. High levels may prompt further testing (e.g., cultures, imaging), while stable low levels suggest controlled inflammation.
How long does CRP testing take?
Results are usually available within 24 to 48 hours, depending on lab processing times. Follow-up with your healthcare provider to discuss results and next steps.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (anti-inflammatory foods), exercise, and stress management can influence CRP levels. Maintaining a healthy lifestyle may help keep inflammation in check.
  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