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C-reactive protein (CRP) concentration, serum/plasma

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 identify and monitor inflammation, often used to check for infections or other inflammatory conditions."]

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

Key facts at a glance

LOINC
7824-6
Short code
C trach Ab Ser-aCnc
Synonyms
C trach Ab Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 CRP Matters in Your Health

CRP is a marker that signals your body’s immune response. High levels may indicate inflammation caused by infections, injuries, autoimmune diseases, or other conditions like heart disease.

When This Test Is Ordered

Your healthcare provider may order CRP to monitor chronic conditions (e.g., rheumatoid arthritis), check for infections, assess heart health, or evaluate response to treatment for inflammation.

What to Expect Before the Test

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

Possible Results and Next Steps

Results are typically reported in milligrams per liter (mg/L). High CRP levels may prompt further testing, like blood cultures or imaging, to find the cause of inflammation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP’s Role in Healthcare

Short name

CRP

Frequently asked questions

How often should I get this test?
Your provider will determine frequency based on your health needs. For example, people with chronic conditions like heart disease may get CRP tests every few months.
Can diet or exercise affect CRP levels?
Yes! Reducing inflammation through diet (e.g., Mediterranean diet), exercise, and managing stress can lower CRP levels. Avoiding smoking and limiting alcohol also helps.
What if my CRP is elevated but I feel fine?
Elevated CRP doesn’t always mean you’re sick. It could signal hidden inflammation, so discuss results with your provider. They may recommend lifestyle changes or additional tests.
  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