CRP

C-Reactive Protein, commonly known as CRP, is a protein produced by the liver that rises sharply — often within just 6 to 8 hours — in response to inflammation or tissue injury anywhere in the body.

Because CRP responds so quickly and dramatically to inflammation, it's widely used as a general, sensitive marker to detect and track the severity of infections, autoimmune flare-ups, and inflammatory conditions.

Unlike more specific tests that look for one particular disease, CRP doesn't tell your doctor exactly what's causing the inflammation — only that inflammation is present and, through serial testing, whether it's improving or worsening.

This makes CRP especially valuable for monitoring how a patient is responding to treatment for infections or inflammatory diseases, since levels typically fall quickly once the underlying problem resolves.