C-reactive protein (CRP) measured by chemiluminescent immunoassay (CLIA) in plasma
This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.
["CRP helps doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after injury."]
Key facts at a glance
- LOINC
- 63427-9
- Short code
- EC stx1 Spec QI NAA+probe
- Synonyms
- EC stx1 Spec QI NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order CRP testing to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate symptoms such as fever, pain, or swelling. It can also help guide treatment decisions or track how well a condition is responding to treatment.
What Does a High or Low CRP Level Mean?
A higher-than-normal CRP level often indicates inflammation, which can be caused by infections, injuries, or certain diseases. A very low level may suggest no active inflammation, but it’s not always definitive. Your doctor will interpret results in the context of your overall health and symptoms.
Sample Preparation and Testing Process
Blood is drawn from a vein in your arm, and the plasma is separated and sent to a lab for testing. The CRP level is measured using a sensitive immunoassay method to detect even small amounts of the protein.
Common Conditions Monitored with CRP
CRP is commonly used to monitor conditions like rheumatoid arthritis, inflammatory bowel disease, heart disease, or infections. It can also help assess the risk of future health problems, such as heart attacks or strokes, in some cases.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CRP plays a key role in identifying and managing inflammatory processes in the body. While it’s not specific to any single disease, elevated levels often signal widespread inflammation that may require further investigation or treatment adjustments. Doctors use CRP as part of a broader diagnostic and monitoring toolkit.
Short name
CRP (Plasma)
Frequently asked questions
What does a CRP test measure exactly?
How often should I get a CRP test?
Can CRP levels change without a clear reason?
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