C-reactive protein (CRP) with high-sensitivity measurement
This blood test measures a protein produced by your liver in response to inflammation, helping detect low-level inflammation in your body.
["A simple blood test to monitor subtle signs of inflammation, useful for early disease detection or tracking treatment effects."]
Key facts at a glance
- LOINC
- 79158-2
- Short code
- COLDAGG
- Synonyms
- CA 1h p Inc Titr Ser 4 deg C inc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum tube or serum separator tube (SST). Pre-warm tube to 37°C before collection
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- — – 1000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- deg-c-incubation
- CPT
- 86156
- SNOMED
- 38791008
- Specimen volume
- 3-5 mL of whole blood yielding at least 1-2 mL of serum
- Stability
- Serum should be separated and tested promptly. Stable at 37°C for 4 hours. If delayed, freeze at -20°C; avoid refrigerated storage which may cause false-positive agglutination
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to check for signs of inflammation, especially if you have risk factors for conditions like heart disease, arthritis, or infections. It can also help monitor chronic conditions or assess responses to treatments.
What Does the Result Mean?
Results are not given in absolute numbers here, but they’re used to compare against general reference ranges for your age and health status. Elevated levels may signal inflammation, while lower levels may indicate reduced risk of certain health issues.
Common Uses in Healthcare
This test is often used in routine check-ups, especially in adults, to assess cardiovascular risk, evaluate autoimmune conditions, or monitor inflammatory diseases like lupus or rheumatoid arthritis.
How Is the Test Performed?
A small blood sample is taken from your arm, usually by a healthcare professional. The sample is sent to a lab where it’s analyzed to measure CRP levels.
Reference range
Negative or titer <1:64 at 4°C. Titers ≥1:64 are considered clinically significant and may indicate cold agglutinin disease, Mycoplasma pneumoniae infection, or other cold-reactive autoimmune conditionsN/A
No fasting required. Specimen must be kept at 37°C during collection and transport to prevent cold agglutinin adsorption to red blood cells, which can cause false-negative results. Avoid placing sample on ice
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?
What does a low CRP level mean?
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 16, 2026. · Read our editorial policy