C-reactive protein (CRP) by nephelometry (serum/plasma)

What Is C-Reactive Protein?

C-reactive protein (CRP) is a protein produced by your liver in response to inflammation. It rises when your body is fighting infection, injury, or other inflammatory conditions. While CRP itself isn’t the cause of inflammation, it’s a useful indicator to monitor how your body is responding to these processes.

Why Might Your Doctor Order This Test?

Your doctor may order CRP testing to evaluate symptoms like fever, pain, or swelling that suggest inflammation. It’s also used before surgeries to assess risk for complications, to monitor chronic conditions like rheumatoid arthritis or heart disease, or to check for infections like pneumonia or sepsis.

Common Uses in Healthcare

CRP is commonly used in both acute and chronic care settings. In acute care, it helps diagnose or monitor infections, autoimmune diseases, or post-surgical inflammation. In chronic care, it may be part of routine monitoring for conditions like cardiovascular disease or inflammatory bowel disease.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate serum or plasma, which is sent to a lab for analysis using nephelometry—a method that measures how much light scatters when CRP binds to antibodies.