C-reactive protein (CRP) in plasma
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 identify inflammation that may signal underlying health concerns."]
Key facts at a glance
- LOINC
- 97936-9
- Short code
- CAURIS
- Synonyms
- C auris DNA Spec Ql NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Sterile specimen container; serum separator tube (SST) or red-top tube for serum specimens
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- CPT
- 87811
- SNOMED
- 428531000124104
- Specimen volume
- 1-2 mL of serum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-70°C or below): 30 days
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 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 responses to treatments for these conditions. It can also be used in screening for certain risks, such as cardiovascular disease.
What Does a High or Low Level Mean?
Elevated CRP levels often indicate inflammation, which can be caused by infections, autoimmune diseases, or other health issues. Lower-than-normal levels may suggest reduced inflammation, but they don’t always mean you’re healthy. Your results will be interpreted by your healthcare provider based on your overall health and medical history.
What to Expect During the Test
A blood sample is taken from a vein, usually in your arm. You may feel a slight pinch, but it’s generally quick and painless. No special preparation is usually needed, though your provider may advise fasting or avoiding certain activities depending on the reason for the test.
Common Conditions Monitored
CRP is commonly monitored in conditions like rheumatoid arthritis, lupus, heart disease, infections (such as pneumonia or sepsis), and after surgeries or injuries to track healing and inflammation levels.
Reference range
Not detectedN/A
No special patient preparation required. Specimen should be collected prior to initiation of antifungal therapy when clinically possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP (Plasma)
Frequently asked questions
CRP is a useful marker for assessing inflammation, but it’s not specific to any single condition. High levels can signal a need for further investigation, while low levels may not rule out inflammation entirely. It’s often used alongside other tests for a complete picture.
How often should I get this test? Your healthcare provider will determine the timing based on your medical needs, such as monitoring chronic conditions or evaluating recent symptoms. Follow their advice for scheduling.
Are there any risks or side effects? Blood tests are generally safe, but you might experience a slight bruise, swelling, or discomfort at the injection site. Rarely, there could be a reaction to the needle or blood draw process.
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