CRP (C-reactive Protein)

C-reactive protein (CRP) is a protein made by the liver and released into the blood in response to inflammation. Its level rises quickly when there is inflammation somewhere in the body and falls again as the inflammation settles, which makes it a useful general marker for detecting and monitoring inflammation.

What it can help assess

• Detecting inflammation: a raised level indicates inflammation somewhere in the body, although it does not identify the exact location or cause
• Identifying possible infection: levels often rise significantly with bacterial infections
• Monitoring inflammatory conditions: it is widely used to track the activity of conditions such as arthritis and to monitor response to treatment
• Following recovery: falling levels can indicate that an infection or inflammation is settling

An important note on interpretation

CRP is a non-specific marker, meaning it tells you that inflammation is present but not what is causing it. Levels can rise with infections, injury, chronic inflammatory conditions, and many other causes. For this reason, the result is always interpreted alongside your symptoms and other clinical information, and a raised result usually means further assessment is needed rather than giving a diagnosis on its own.

Why it matters

CRP is a simple and valuable test for picking up inflammation that might otherwise go unnoticed, and for tracking known inflammatory conditions over time. Any raised or abnormal result should be discussed with your GP, who can consider the likely cause in the context of your overall health and advise on any further testing needed.