Serum or plasma concentration of C-reactive protein (CRP) measured by nephelometry
This test measures the level of C-reactive protein, a protein produced by your liver in response to inflammation or infection.
["CRP helps doctors assess inflammation in your body."]
Key facts at a glance
- LOINC
- 23266-0
- Short code
- M cap caprip Ab Ser Ql CF
- Synonyms
- M cap caprip Ab Ser Ql CF
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- comp-fix
- 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, infections, autoimmune conditions, or other health issues. It’s often used alongside other tests to monitor conditions like heart disease, arthritis, or kidney problems.
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 metabolic or liver evaluation. Bring any medications you’re taking to your appointment.
How the Test Is Performed
Blood is drawn from a vein, typically in your arm, using a needle. You may feel a small pinch, but it usually doesn’t cause discomfort. The blood sample is sent to a lab for analysis.
What the Results Mean
Results are reported in milligrams per deciliter (mg/dL). Higher than normal levels may indicate inflammation, infection, or other health concerns. Your doctor will interpret the results in the context of your medical history and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CRP is a useful marker for monitoring inflammation. Elevated levels can signal conditions like infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., rheumatoid arthritis), or complications from chronic illnesses (e.g., heart disease). Low levels may suggest no active inflammation, but they don’t rule out all causes. Your doctor will use these results to guide treatment or further testing.
Short name
CRP (Nephelometry)
Frequently asked questions
How long does it take to get my CRP test results?
Can I eat or drink before this test?
Is there anything I should avoid doing before the 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