C-Reactive Protein
A general marker of inflammation or infection anywhere in the body.
| Typical reference range | below 8 mg/L |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Standard CRP uses a less sensitive assay than hs-CRP and is designed to detect larger rises in this liver-made inflammatory protein, which can increase a thousandfold within 1-2 days of infection or injury.
Why it matters
CRP helps detect and monitor infections, inflammatory diseases (such as rheumatoid arthritis and IBD) and response to treatment.
What a high result can mean
High values occur with bacterial and some viral infections, autoimmune flares, tissue injury, surgery, burns and some cancers; very high values (above 100 mg/L) usually indicate serious bacterial infection.
What a low result can mean
Low values indicate no significant acute inflammation.
What affects the result
Rises quickly and falls within days of resolution, making it useful for monitoring. For cardiovascular risk assessment, use hs-CRP.
Units and conversion
Usually reported in mg/L.
- From mg/dL: multiply by 10 to get mg/L
- From ug/mL: multiply by 1 to get mg/L
- From nmol/L: multiply by 0.105 to get mg/L
Also called on lab reports
CRP, C Reactive Protein, C-Reactive Protein (CRP), CRP, Quantitative, C-Reactive Protein, Quant
Related tests: Inflammation & Immunity
This page is educational and does not replace advice from a healthcare professional.