C-reactive protein (CRP) mass concentration in serum/plasma

Why This Test Matters

CRP is a marker for inflammation, which can occur due to infections, injuries, or certain medical conditions. High levels may signal an ongoing inflammatory process that your doctor needs to address.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm. Tell your doctor about any medications or supplements you’re taking, as some may affect results.

This test is often used to monitor chronic inflammatory conditions, check for infections, or evaluate response to treatments like steroids.

CRP levels may be checked in people with suspected infections (e.g., pneumonia, urinary tract infections), autoimmune diseases (e.g., rheumatoid arthritis), or after surgery to monitor healing.

Results are not always given in absolute numbers, but doctors compare them to your baseline or to others in your condition. Very high or very low levels may prompt further testing or discussions with your provider.

Interpretation depends on your medical history, symptoms, and other test results. For example, elevated CRP may indicate inflammation, while very low levels might suggest suppressed immune response.