C-reactive protein (CRP) in serum/plasma by nephelometry
This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation or infection in your body.
["CRP helps doctors assess inflammation, infection, or risk of future health issues like heart disease."]
Key facts at a glance
- LOINC
- 82178-5
- Short code
- C pneum DNA Nph Ql NAA+n-prb
- Synonyms
- C pneum DNA Nph Ql NAA+n-prb
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- non-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 arthritis, heart disease, or infections, or evaluate risk factors for diseases such as autoimmune disorders or cardiovascular problems.
What Does a High or Low CRP Level Mean?
Elevated CRP levels often indicate inflammation or infection, but they can also be influenced by other factors like stress, certain medications, or obesity. Low levels generally suggest reduced inflammation, but they don’t always mean you’re healthy.
Sample Collection and Preparation
A blood sample is taken from a vein, usually in your arm. The blood is processed to separate serum or plasma, which is then analyzed using a specialized nephelometry method to measure CRP levels accurately.
Common Conditions Monitored
This test is commonly used to monitor conditions like rheumatoid arthritis, lupus, heart disease, infections, and to assess the risk of future health problems such as heart attacks or strokes.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP is a marker for systemic inflammation. While it doesn’t diagnose specific conditions, it helps guide treatment decisions, track disease progression, and evaluate responses to therapy. Elevated CRP may prompt further investigation into underlying causes, such as infections, autoimmune diseases, or metabolic disorders.
Short name
CRP (Nephelometry)
Frequently asked questions
What causes CRP levels to change?
How often should I get this test?
Can I prepare for this test in any special way?
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