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C-reactive protein, serum concentration

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

This blood test measures the level of C-reactive protein, a protein made by your liver in response to inflammation or infection in your body.

Quick summary

["CRP helps doctors assess inflammation, track infections, or monitor conditions like arthritis or heart disease."]

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

Key facts at a glance

LOINC
24848-4
Short code
CT Orbit-Bl
Synonyms
CT Orbit-Bl
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 this test to check for signs of inflammation, monitor chronic conditions, or evaluate whether an infection is spreading. It can also help determine if you’re healing after surgery or an injury.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood, which usually takes a few minutes. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Higher-than-normal CRP levels may indicate inflammation, infections, or autoimmune diseases. Lower levels suggest reduced inflammation. Your provider will discuss results in the context of your health.

Common Conditions Monitored

CRP is often used to monitor conditions like rheumatoid arthritis, heart disease, infections (e.g., pneumonia, sepsis), or after surgeries to check healing progress.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum)

Frequently asked questions

How often should I get this test?
Your provider will determine the frequency based on your health needs. For example, people with chronic conditions like arthritis may get it monthly or quarterly, while others may need it only occasionally.
Can diet or exercise affect CRP levels?
Yes! Diet high in fruits, vegetables, and omega-3s may lower CRP, while processed foods or obesity can raise it. Regular physical activity tends to reduce inflammation, but results vary by individual.
Is there anything I should avoid before the test?
Avoid heavy meals 2 hours before testing, but light snacks are fine. If you’re on blood thinners, check with your provider to ensure safe timing.
  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