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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.

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
77451-3
Short code
CTA T Ao+Abd Ao+Ves-Bl for endograf
Synonyms
CTA T Ao+Abd Ao+Ves-Bl for endograf
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct-angio
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 This Test Might Be Ordered

Your healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. It can also help diagnose infections or identify risks for conditions like heart disease.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re concerned about pain or discomfort, let your provider know.

What the Results Mean

Higher CRP levels often indicate inflammation, but results alone don’t diagnose a specific condition. Your provider will review your full medical history and other test results to interpret the meaning.

Common Conditions Monitored

Elevated CRP is commonly seen in infections (like pneumonia or urinary tract infections), autoimmune diseases (like rheumatoid arthritis), or after injuries or surgeries. It can also be a marker for long-term risks like heart disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

Frequently asked questions

How often will I need this test?
Your provider will determine how often you need this test based on your health condition and treatment plan. Some people may need it monthly, quarterly, or only occasionally.
Can lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Reducing inflammation through healthy habits may lower your CRP over time.
What if my CRP is high but I don’t have symptoms?
A high CRP might indicate underlying inflammation even without obvious symptoms. Your provider will investigate further, possibly with additional tests or lifestyle recommendations.
  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