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C-reactive protein (CRP) in plasma by chemiluminescent immunoassay (CLIA)

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
95765-4
Short code
CAURIS
Synonyms
C auris DNA Spec Ql NAA+n-prb
Category
chemistry
Sample
serum
Container
Sterile, leak-proof container; preferred swab in transport medium (e.g., Copan ESwab or BD ESwab) for axilla/groin composite swabs; blood culture bottles for blood specimens; sterile urine container for urine; appropriate sterile containers for tissue or fluid specimens
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
non-probe-amp-tar
CPT
87481
SNOMED
122450006
Specimen volume
1 swab (axilla/groin composite recommended for screening); 8-10 mL blood per culture bottle; 10 mL urine; variable for tissue/fluid specimens
Stability
Room temperature: up to 24 hours for swabs in transport medium. Refrigerated (2-8°C): up to 7 days for swabs. Blood culture bottles: as per blood culture protocol. Specimens should be processed as soon as possible after collection to maintain nucleic acid integrity.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
8–72 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions like arthritis, or evaluate responses to treatments. It can also help identify infections or other health issues where inflammation plays a role.

What to Expect Before the Test

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

What Does the Test Result Mean?

Higher-than-normal levels may indicate inflammation, infections, or certain diseases. Lower-than-normal levels might suggest reduced immune response or certain medical conditions. Your provider will interpret results in the context of your overall health.

Common Conditions Monitored

CRP is often used to monitor conditions like rheumatoid arthritis, lupus, heart disease, or infections. It can also help track how well treatments are working or if inflammation is worsening.

Reference range

Negative (Not Detected)N/A

Specimen: serum

No special patient preparation required. Specimen should be collected prior to initiation of antifungal therapy when possible. Contact the laboratory prior to collection for proper specimen collection kit and transport conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP is a marker for inflammation and is used broadly in medicine to guide diagnosis, treatment planning, and follow-up. Elevated CRP levels can signal conditions like infections, autoimmune diseases, or tissue damage, while lower levels may suggest reduced inflammation or immune activity. Always discuss results with your healthcare provider for personalized insights.

Short name

CRP (Plasma)

Frequently asked questions

What does a high CRP level mean?
A high CRP level often means there is inflammation in your body, which could be due to infections, autoimmune diseases, or other health issues. Your provider will review it with your other symptoms and test results to determine the cause.
How often should I get this test?
Your provider will decide how often you need this test based on your health needs. Some people get it once a year, while others may need it more often if they have ongoing conditions like arthritis or heart disease.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a healthy diet, staying active, and avoiding smoking may help lower inflammation and CRP levels 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