C-reactive protein (CRP) with high-sensitivity measurement by turbidimetry/nephelometry
This test measures a protein produced by the liver in response to inflammation, helping detect low-level inflammation in your body.
["A simple blood test to check for subtle signs of inflammation, often used alongside other tests for conditions like heart disease or autoimmune disorders."]
Key facts at a glance
- LOINC
- 91671-8
- Short code
- CDT-IFCC
- Synonyms
- CDT Disialo/Tf per IFCC-RMP CDT MFr S/P
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plasma acceptable in lithium heparin or EDTA tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 1.7
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- High-Performance Liquid Chromatography (HPLC) or Capillary Electrophoresis standardized per IFCC-RMP reference measurement procedure
- CPT
- 83516
- SNOMED
- 395142001
- Specimen volume
- 2 mL serum or plasma (minimum 1 mL)
- Stability
- Serum/plasma stable for 7 days at 2-8°C; for longer storage, freeze at -20°C for up to 3 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to monitor chronic conditions like heart disease, rheumatoid arthritis, or other inflammatory diseases. It’s also used to assess risk for conditions like cardiovascular disease or to check for infection or injury before surgery.
What Does the Result Mean?
Results are not given in absolute numbers but are compared to a reference range for your age and health status. Elevated levels may indicate inflammation, infection, or other health concerns, while very low levels might suggest an absence of inflammation.
How Is the Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The blood is processed to measure CRP levels using a specialized lab technique that detects even small amounts of this protein.
What Are Common Causes of Abnormal Results?
Elevated CRP can be caused by infections (like a cold or urinary tract infection), injuries, surgeries, or certain medical conditions (like lupus or heart disease). Very low levels may occur with certain medications or in people with very low inflammation.
Reference range
CDT (Disialo/Total Transferrin ratio): <1.7% considered normal; 1.7-2.0% borderline; >2.0% indicative of chronic alcohol consumption (per IFCC-RMP standardization)N/A
No fasting required. Patient should abstain from alcohol for at least 1-2 weeks prior to testing if screening for chronic alcohol use. Avoid recent blood transfusion as it may affect transferrin measurements.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP is a marker for systemic inflammation and is often used as a screening tool for conditions that don’t cause obvious symptoms. It helps guide decisions about treatment, monitoring, or further testing, especially in patients with chronic illnesses or at higher risk for cardiovascular events.
Short name
hs-CRP (high-sensitivity C-reactive protein)
Frequently asked questions
What does a high CRP level mean?
How often should I get this test?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 15, 2026. · Read our editorial policy