What is this test?
CRP is a protein that the liver increases during inflammation. It indicates that there is an inflammatory reaction in the body, but does not indicate where the cause is.
Why might it be ordered?
- With symptoms of infection or other acute inflammation.
- To monitor whether inflammatory activity and response to treatment change.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
CRP may rise with bacterial or viral infection, trauma, surgery and many inflammatory conditions. A low value does not rule out every cause of inflammation. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.