C-reactive protein (CRP) concentration in serum/plasma
This test measures the level of C-reactive protein, a protein made by your liver in response to inflammation in your body.
["CRP helps identify and monitor inflammation, often used to check for infections, autoimmune conditions, or other health issues."]
Key facts at a glance
- LOINC
- 86688-9
- Short code
- RVC Spec Ql Cult
- Synonyms
- RVC Spec Ql Cult
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- organism-specific-culture
- 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 evaluate signs of inflammation, assess risk for heart disease, or monitor conditions like arthritis, infections, or other inflammatory diseases. It can also help guide treatment decisions.
What to Expect Before the Test
No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before the draw if your lab requires it, but this is not always the case for CRP. Bring any medications or questions to your appointment.
What Happens During the Test?
A healthcare provider will draw blood from a vein, usually in your arm. You may feel a small pinch, but it usually doesn’t cause significant discomfort. The test takes a few minutes, and you can resume normal activities afterward.
What Does the Test Result Mean?
Results are interpreted based on your overall health and symptoms. Higher-than-normal levels may suggest inflammation, infections, or certain diseases, while lower levels may indicate reduced inflammation. Your doctor will discuss the meaning of your specific result with you.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP
Frequently asked questions
CRP is a marker for inflammation and is often used alongside other tests to diagnose conditions like infections, autoimmune diseases (e.g., rheumatoid arthritis), or cardiovascular risks. It can also help track how well treatments are working.
CRP is not a definitive test for a single disease but is often used as part of a broader evaluation. It’s important to discuss your results with your healthcare provider.
If you have a history of high CRP levels, your doctor may recommend lifestyle changes (like diet or exercise) or medications to help manage inflammation.
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