Serum or plasma mass concentration of C-reactive protein (CRP)
This test measures the amount of C-reactive protein in your blood. CRP is a protein produced by your liver in response to inflammation or infection.
["CRP helps your doctor assess inflammation in your body."]
Key facts at a glance
- LOINC
- 74518-2
- Short code
- CC16
- Synonyms
- CC16 Ser-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 20
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (e.g., ELISA, nephelometry)
- CPT
- 83519
- SNOMED
- 121781000
- Specimen volume
- 1 mL serum
- Stability
- Stable for 24 hours at room temperature, 7 days at 2-8°C, or 3 months at -20°C. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–120 hours
- Order
- routine
What Is C-Reactive Protein (CRP)?
C-reactive protein (CRP) is a marker produced by your immune system when tissues are damaged or inflamed. It’s often measured to check for signs of infection, inflammation, or other health issues like heart disease.
Why Might You Need This Test?
Your doctor may order this test to monitor conditions like rheumatoid arthritis, heart disease, or infections. It can also help track how well treatments for inflammation are working.
How Is the Test Done?
A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab for testing. The test measures the protein’s concentration in your serum or plasma.
What Does the Result Mean?
Higher CRP levels may indicate inflammation, infections, or other health problems. Your doctor will interpret the result in relation to your symptoms and medical history.
Reference range
Reference values vary by assay methodology; generally <20 ng/mL in healthy non-smoking adults. Smokers typically show elevated levels.N/A
No special preparation required. Smoking status should be documented as it significantly affects CC16 levels.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CRP is a useful tool for detecting and monitoring inflammation. Elevated levels can signal conditions like infections, autoimmune diseases, or cardiovascular risks, helping doctors guide treatment decisions.
Short name
CRP Mass Concentration
Frequently asked questions
Why do doctors sometimes check CRP levels even if I don’t have symptoms?
Can CRP levels change with diet or exercise?
What if my CRP test result is very 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