C-reactive protein, serum/plasma concentration (high-sensitivity)
This test measures the level of a protein called C-reactive protein (CRP) in your blood. CRP is produced by your liver in response to inflammation, helping your body fight infection or injury.
["CRP helps doctors assess inflammation, even when symptoms aren’t present."]
Key facts at a glance
- LOINC
- 78514-7
- Short code
- N men sg A+B+C+W135+Y+EcK1 Ag Spec Ql LA
- Synonyms
- N men sg A+B+C+W135+Y+EcK1 Ag Spec Ql LA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- la
- CPT
- 82553
- 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 heart disease, arthritis, or autoimmune disorders, or evaluate how your body is responding to infection or injury. High levels may indicate conditions such as infections, autoimmune diseases, or other inflammatory processes.
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 blood is drawn from a vein. If you’re taking blood from a fingerstick (e.g., for a home test), no fasting is required. Always follow your provider’s instructions.
What Happens During the Test?
A healthcare professional will collect a small sample of blood, either from a vein in your arm or by pricking your finger. The blood is then sent to a lab for analysis. Results are typically available within 24–48 hours.
What the Results Mean
Results are interpreted by your healthcare provider based on your medical history and symptoms. Elevated levels may signal inflammation, while normal or low levels suggest minimal inflammation. There’s no single reference range for everyone, so your provider will discuss what your results mean for you.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CRP is a useful marker for detecting and monitoring inflammation in conditions like cardiovascular disease, rheumatoid arthritis, or sepsis. It can also help track how well treatments are working for inflammatory diseases. However, CRP alone isn’t diagnostic—it’s often used alongside other tests and clinical findings.
Short name
hs-CRP
Frequently asked questions
How long does it take to get my CRP test results?
Can I eat or drink before this test?
Does CRP test show if I have an infection?
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 17, 2026. · Read our editorial policy