C-reactive protein (CRP) by nephelometry
This test measures the level of C-reactive protein in your blood, a marker often checked for signs of inflammation or infection.
["CRP helps track inflammation, guiding decisions about treatments or further tests."]
Key facts at a glance
- LOINC
- 110953-7
- Short code
- GQ1b Gangl IgG Msmt Ser
- Synonyms
- GQ1b Gangl IgG Msmt Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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
What Is C-Reactive Protein?
C-reactive protein (CRP) is a protein produced by your liver in response to inflammation. It rises when your body fights infections, injuries, or other conditions causing inflammation. While CRP itself isn’t the cause of inflammation, it’s a useful indicator to help doctors assess whether inflammation is present and guide treatment plans.
Why Might You Need This Test?
Doctors may order CRP tests to monitor conditions like heart disease, autoimmune disorders (e.g., rheumatoid arthritis), infections, or after surgery to check for complications. It can also help evaluate symptoms such as fever, joint pain, or unexplained swelling.
How Is the Test Performed?
A 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 CRP is present in your serum.
What Do Results Mean?
Results are typically reported in milligrams per liter (mg/L). Higher than normal levels may suggest inflammation, infection, or other health issues. Your doctor will interpret results in the context of your overall health and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CRP is a key marker for inflammation, helping doctors diagnose and manage conditions like cardiovascular disease, infections, or autoimmune disorders. High CRP levels may prompt further testing or adjustments to treatment plans, while low levels may indicate reduced inflammation. It’s often used alongside other tests for a fuller picture of your health.
Short name
CRP
Frequently asked questions
What causes CRP levels to change?
How long does it take to get results?
Can I prepare for this 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