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C-reactive protein (CRP) by nephelometry

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

This test measures a protein in your blood that rises when your body is fighting inflammation, often used to check for low-grade inflammation or infection.

Quick summary

["Helps track subtle signs of inflammation that may not show up with other tests."]

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

Key facts at a glance

LOINC
14474-1
Short code
C trach Ag UrnS Ql IA
Synonyms
C trach Ag UrnS Ql IA
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

High-sensitivity CRP (hs-CRP) is a blood test that detects very small amounts of C-reactive protein, a marker for inflammation. It can help identify risks for conditions like heart disease, even when symptoms aren’t present.

What to Expect Before the Test

No special preparation is needed, but you may fast for 8–12 hours before the blood draw if instructed by your provider. Wear a comfortable shirt for easy access to your arm.

How the Test Works

A small sample of blood is taken from your arm and sent to a lab. The lab uses a special technique called nephelometry to measure CRP levels precisely.

Common Uses

Doctors may order this test to assess inflammation in conditions like heart disease, autoimmune disorders, or after surgery to monitor healing.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (High Sensitivity)

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present, which could signal infection, injury, or chronic conditions like arthritis or heart disease. Your doctor will interpret results in the context of your overall health.
How often should I get this test?
Your doctor will determine how often you need this test based on your medical history, symptoms, and treatment plan. Some people get it yearly or more often if they have a higher risk for inflammation-related conditions.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a heart-healthy diet, staying active, and avoiding smoking may help lower CRP and reduce inflammation over time.
  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