C-reactive protein (CRP) by nephelometry (high-sensitivity)
This blood test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body. It helps assess whether inflammation is present, even if you don’t have obvious symptoms.
["This test helps track inflammation, aiding in early detection of conditions like infections, autoimmune diseases, or heart disease risk."]
Key facts at a glance
- LOINC
- 105789-2
- Short code
- P aerug regA Ct Bld Pos Qn NAA+probe
- Synonyms
- P aerug regA Ct Bld Pos Qn NAA+probe
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order a high-sensitivity CRP test to monitor chronic conditions like rheumatoid arthritis or lupus, check for signs of infection, or evaluate your risk for heart disease. It’s also used to assess response to treatments that target inflammation.
What to Expect Before the Test
No special preparation is needed. You may fast before the test, but this does not affect CRP levels. Bring any medications you’re currently taking, as some may influence results.
What Happens During the Test?
A small blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed using nephelometry, a method that measures how much light scatters from CRP particles in your blood.
What Are the Results Measured Against?
Results are compared to a general reference range for CRP levels, though individual ranges may vary by lab. High levels may indicate active inflammation, while low levels suggest reduced inflammation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated CRP levels often signal inflammation, which can be linked to infections, autoimmune disorders, or cardiovascular risks. Repeatedly high levels may prompt further investigation into underlying causes, such as chronic conditions or lifestyle factors. Low or normal levels suggest minimal inflammation, but they don’t rule out other conditions entirely.
Short name
High-sensitivity CRP (hs-CRP)
Frequently asked questions
How long does it take to get my results?
Can diet or exercise affect CRP levels?
What if my CRP levels are high?
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