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C-reactive protein (CRP) by nephelometry

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

This test measures a protein produced by your liver in response to inflammation, helping detect or monitor conditions causing swelling or infection.

Quick summary

["High CRP levels may signal inflammation, often used to track chronic conditions or infections."]

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

Key facts at a glance

LOINC
22210-9
Short code
C immitis IgM Ser Ql
Synonyms
C immitis IgM Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 this test to check for inflammation, monitor chronic diseases (like arthritis or heart disease), or evaluate symptoms such as fever, fatigue, or joint pain that could indicate an infection or autoimmune condition.

What Does the Result Mean?

Results are not given in a single range but are compared to your doctor’s clinical judgment. Very high levels may suggest severe inflammation, while low levels might indicate no active inflammation. Your doctor will interpret results based on your symptoms and medical history.

Common Conditions Monitored

This test is often used to monitor conditions like rheumatoid arthritis, inflammatory bowel disease, or heart disease. It may also help assess response to treatments or detect early signs of infections.

Sample Collection and Preparation

A blood sample is taken from a vein in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort. The blood is sent to a lab where it is analyzed using a specialized method called nephelometry to measure CRP levels precisely.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (High-Sensitivity)

Frequently asked questions

CRP is a marker for inflammation, meaning it rises when your body fights infection, injury, or disease. While it doesn’t diagnose conditions directly, it helps doctors track inflammation levels over time and guide treatment decisions.
This test is quick and painless, typically done during a regular blood draw. Results are usually available within a few days, depending on lab processing times.
You may experience mild bruising or soreness at the injection site, but this usually fades quickly. Avoid strenuous activity for a day after the test to prevent excessive bleeding.
If you have a bleeding disorder or take blood-thinning medications, let your doctor know before the test to ensure safe sample collection.
Is there anything I should do to prepare?
No special preparation is needed, but avoid heavy meals or alcohol before the test to ensure accurate results. If you’re unsure, ask your doctor for personalized advice.
  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