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C-reactive protein (CRP) mass concentration in 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 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
53434-7
Short code
CPT2 Amnc-cCnt
Synonyms
CPT2 Amnc-cCnt
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85610
SNOMED
396252006
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why CRP Matters in Your Health

CRP is a marker that signals when your body is fighting inflammation. High levels may indicate conditions such as infections, injuries, or certain inflammatory diseases. Your doctor may order this test to check for these issues or to monitor treatment progress.

When This Test Is Done

CRP tests are often performed when you have symptoms like fever, pain, or swelling, or if you have a known condition that causes inflammation. They may also be done regularly in people at higher risk for heart disease or autoimmune disorders.

What to Expect Before the Test

You’ll typically have a small needle inserted into your arm to draw blood. The process is quick and usually painless. No special preparation is needed, but avoid heavy meals before the test if instructed by your doctor.

What the Results Mean

Results are compared to a general reference range, but your doctor will interpret them based on your specific health situation. Very high levels may require further investigation, while low levels might suggest no active inflammation.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: fluid

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CRP (Serum/Plasma)

Frequently asked questions

What does CRP measure?
CRP measures the amount of C-reactive protein in your blood, which rises when your immune system responds to inflammation, infections, or tissue damage.
Can CRP levels change with diet or exercise?
Diet and exercise can influence inflammation indirectly, but CRP levels are primarily affected by underlying health conditions rather than lifestyle alone. Your doctor will consider these factors when interpreting results.
How often should CRP be checked?
Your doctor will determine how often to check CRP based on your medical history, symptoms, and treatment plan. Regular monitoring may be needed for chronic conditions like heart disease or arthritis.
  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