C-reactive protein (CRP) with high-sensitivity measurement
This blood test measures a protein produced by your liver in response to inflammation, often used to assess low-level inflammation in the body.
["Helps track subtle signs of inflammation that may not be obvious otherwise."]
Key facts at a glance
- LOINC
- 79157-4
- Short code
- COLDAG22
- Synonyms
- CA 1h p Inc Titr Ser 22 deg C inc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube, pre-warmed to 37°C
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- — – 1000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- deg-c-incubation
- CPT
- 86156
- SNOMED
- 109081007
- Specimen volume
- 3-5 mL whole blood (minimum 1 mL serum)
- Stability
- Specimen must be maintained at 37°C until serum is separated. Separated serum stable at 2-8°C for 24 hours; for longer storage, freeze at -20°C. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 300
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to monitor conditions like heart disease risk, autoimmune disorders, or infections. It’s also used to check for inflammation after surgery or injury.
What to Expect During the Test
A small blood sample is taken from your arm. You may feel a slight pinch, but it usually takes only a few minutes. No special preparation is needed.
How Results Are Interpreted
Results are compared to general reference ranges for healthy adults, though individual values can vary. Higher than normal levels may signal inflammation, while lower levels could indicate reduced inflammation.
Common Conditions Monitored
Elevated CRP levels may be linked to conditions like coronary artery disease, rheumatoid arthritis, or other inflammatory diseases. It’s not diagnostic on its own but supports broader evaluation.
Reference range
Negative or <1:64 (titer less than 1:64 considered negative or clinically insignificant). Titer ≥1:64 suggests cold agglutinin disease or cold autoimmune hemolytic anemia, particularly when associated with clinical hemolysis.N/A
No special patient preparation required. Sample should be kept at 37°C during collection and transport to prevent cold agglutinin binding and false-negative results. Avoid cooling the specimen before serum separation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
hs-CRP (high-sensitivity C-reactive protein)
Frequently asked questions
What does a high CRP level mean?
Can I eat or drink before this test?
How often should I get 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