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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 in your blood, a protein produced by your liver in response to inflammation or infection.

Quick summary

["CRP helps doctors assess inflammation, infection, or risk of future health issues like heart disease."]

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

Key facts at a glance

LOINC
93192-3
Short code
HTR2C c.551-3008C>G Geno Bld/T
Synonyms
HTR2C c.551-3008C>G Geno Bld/T
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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 like arthritis or heart disease, or evaluate symptoms such as fever, pain, or swelling that suggest infection or injury. It can also help track how well treatments are working.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re on blood thinners, let your doctor know before the test to avoid unusual bleeding.

What the Results Mean

Higher CRP levels often indicate inflammation, but they can also be raised in conditions like infections, autoimmune diseases, or after surgery. Your doctor will compare your results to your health history and other tests to interpret them correctly.

Common Conditions Monitored

This test is commonly used to monitor conditions like rheumatoid arthritis, heart disease, or kidney disease. It may also help detect early signs of infections or assess how well you’re responding to treatments for these conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP is a marker for inflammation and can signal underlying health risks, such as cardiovascular disease or autoimmune disorders. While it doesn’t diagnose a specific condition, it helps guide treatment decisions and track disease activity over time.

Short name

CRP (Nephelometry)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present in your body, which could be due to infection, injury, autoimmune disease, or other health conditions. Your doctor will review your results alongside other factors to determine the cause.
Can I eat or drink before this test?
You can eat and drink normally before this test unless your doctor has specific instructions. No fasting is required for CRP testing.
Will this test hurt?
You may feel a slight pinch when the needle is inserted, but the procedure usually takes only a few minutes. Most people experience minimal discomfort afterward.
  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