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C-reactive protein (CRP) by turbidimetry

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.

Quick summary

["CRP helps doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
26226-1
Short code
CT Extr-L
Synonyms
CT Extr-L
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
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 healthcare provider may order a CRP test to check for signs of inflammation. This can help diagnose conditions like infections, heart disease, or inflammation-related illnesses, or monitor treatment progress.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, similar to other blood tests. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Higher CRP levels often indicate inflammation, but results depend on your overall health and medical history. Your provider will interpret the results in the context of your symptoms and other tests.

Common Conditions Monitored

CRP is commonly used to track conditions like rheumatoid arthritis, infections (e.g., pneumonia), heart disease, or after surgeries to check for complications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum)

Frequently asked questions

What causes CRP levels to change?
CRP levels rise in response to infections, injuries, autoimmune diseases, or other inflammatory processes. Stress, certain medications, or recent surgeries can also temporarily affect levels.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing time. Your provider will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
You can eat and drink normally before the test unless instructed otherwise. Avoiding food or fluids for blood tests is usually not required for CRP.
  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