C-reactive protein (CRP) concentration, plasma
This test measures the level of C-reactive protein in your blood plasma. CRP is a protein produced by your liver in response to inflammation, helping your body identify and fight infections or injuries.
["CRP helps track inflammation, guiding decisions about treatment or further testing."]
Key facts at a glance
- LOINC
- 70163-1
- Short code
- C trach+GC pnl Cvx NAA+probe
- Synonyms
- C trach+GC pnl Cvx 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 healthcare provider may order this test to check for signs of inflammation, monitor conditions like rheumatoid arthritis, infections, or heart disease, or evaluate responses to treatments. It can also help assess risk for certain health issues over time.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader panel, but this isn’t always required for CRP alone. Bring any medications you’re currently taking.
How the Test Works
A small blood sample is drawn from a vein, typically in your arm. The blood is processed to separate plasma, which is then tested for CRP levels using a sensitive immunoassay method to detect even small amounts of the protein.
What the Results Mean
Results are reported in milligrams per liter (mg/L). Higher than normal levels may indicate inflammation, infection, or other underlying conditions. Your provider will interpret results in the context of your overall health and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP is a marker of systemic inflammation. Elevated levels may signal acute infections (e.g., pneumonia), chronic inflammatory diseases (e.g., lupus), or conditions like cardiovascular disease. It’s often used alongside other tests to guide treatment plans, such as adjusting medications or identifying risk factors for long-term health concerns.
Short name
CRP (Plasma)
Frequently asked questions
What causes CRP levels to rise?
How long does it take to get results?
Can I lower my CRP levels naturally?
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