C-reactive protein (CRP) by turbidimetry (serum/plasma)
This blood test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.
["CRP helps doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]
Key facts at a glance
- LOINC
- 105806-4
- Short code
- CAURISPCR
- Synonyms
- C auris DNA Ct Bld Pos Qn NAA+probe
- Category
- chemistry
- Sample
- whole-blood
- Container
- Positive blood culture bottle submitted for testing; aliquot transferred to sterile molecular-grade tube for nucleic acid extraction
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- CPT
- 87481
- SNOMED
- 446080008
- Specimen volume
- 1-2 mL aliquot from positive blood culture bottle
- Stability
- Reflex testing should be performed from positive blood culture as soon as flag is detected. If subculture aliquot is used, stable for 24 hours at 2-8°C or up to 72 hours at -70°C; avoid repeated freeze-thaw cycles
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate how your body is responding to an infection or treatment. It can also be used before surgery to assess risk.
What Does a High CRP Level Mean?
A higher-than-normal CRP level often indicates inflammation. While it doesn’t specify *where* or *why* inflammation is happening, it can signal conditions like infections, autoimmune disorders, or other inflammatory diseases. Always discuss results with your healthcare provider.
What Does a Low CRP Level Mean?
A low CRP level usually means there is less inflammation in your body. However, it doesn’t rule out all causes of inflammation, so your doctor may still recommend further testing or monitoring.
Common Conditions Monitored with CRP
CRP is commonly used to track inflammation in conditions like rheumatoid arthritis, lupus, heart disease, or after procedures like joint replacements. It can also help guide decisions about starting or stopping certain medications.
Reference range
Not detected (Cycle threshold reported qualitatively as positive when detected); Ct value reported quantitatively when positive (lower Ct values indicate higher organism burden)N/A
No fasting required. Specimen should be collected aseptically from positive blood culture bottles to prevent contamination. Standard blood culture collection protocols apply prior to this reflex testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP’s Role in Healthcare
Short name
CRP (Serum/Plasma)
Frequently asked questions
What factors might affect my CRP test results?
How soon will I get my CRP test results?
Can I eat or drink anything before 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