What it is: A C-reactive protein (CRP) test measures the level of CRP, a protein the liver produces in response to inflammation, in the blood.
Why it's ordered: Ordered to help detect infection or inflammation, assess autoimmune disease activity, or, in a high-sensitivity form, estimate cardiovascular risk.
What it detects: CRP rises within hours of tissue injury, infection, or inflammation and falls as the underlying cause resolves, making it useful for tracking infection or inflammatory disease activity over time, though it doesn't identify the specific cause.
Collection & prep: A standard blood draw from a vein in the arm. No special preparation is typically required for a standard CRP test.
Results:
High – suggests active inflammation or infection somewhere in the body; doesn't identify the location or cause on its own
Normal – generally below about 1 mg/dL (lab-dependent); doesn't rule out localized or mild inflammation
Possible complications of underlying inflammation: Because CRP is non-specific, an elevated result typically prompts further evaluation — symptoms, exam findings, and additional tests — to identify the source rather than serving as a standalone diagnosis.
Statements made in the Clinical Manual have not been evaluated by the FDA. The products mentioned are not intended to diagnose, treat, cure or prevent any disease.
