C-Reactive Protein (CRP) by Immunoassay (Plasma/Serum)
This test measures a protein in your blood that rises when inflammation is present, often used to check for infection, injury, or autoimmune conditions.
["Helps track inflammation levels in your body."]
Key facts at a glance
- LOINC
- 82841-8
- Short code
- ENA PCNA IgG Titr Ser IF
- Synonyms
- ENA PCNA IgG Titr Ser IF
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 8
- Ref high
- 61
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- if
- CPT
- 82977
- SNOMED
- 3110003
- 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 doctor may order this test to monitor signs of inflammation, assess risk for heart disease, or evaluate conditions like infections, arthritis, or other autoimmune diseases. High-sensitivity CRP is particularly useful for detecting low-level inflammation that might not be obvious otherwise.
What to Expect Before the Test
No special preparation is needed. You may have a blood draw from a vein in your arm. If you’re on blood thinners, let your doctor know before the test.
What the Results Mean
Results are not given as a single number but as a trend or comparison to your baseline. Elevated levels may signal inflammation, while normal levels suggest low or stable inflammation. Your doctor will interpret results in the context of your health history and other tests.
Common Conditions Monitored
This test is often used to track conditions like rheumatoid arthritis, lupus, heart disease, or infections. It can also help guide treatment decisions for chronic inflammatory diseases.
Reference range
Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated CRP levels may indicate an active inflammatory process, such as an infection, injury, or autoimmune response. Low or normal levels generally suggest minimal inflammation, but results should always be reviewed by a healthcare provider.
Short name
CRP (High-Sensitivity)
Frequently asked questions
What causes CRP levels to be higher than usual?
How often should I get this test?
Can diet or lifestyle changes affect CRP levels?
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