CRP is often measured in patients with inflammatory diseases, such as some forms of arthritis and autoimmune diseases or in inflammatory bowel disease, to assess how active the inflammation is and to monitor the treatment. CRP is also used to monitor patients after surgery or other invasive procedures to detect the presence of an infection during the recovery period. CRP tests are not specific enough to diagnose a particular disease. Rather, CRP is a general marker of infection and inflammation that alerts medical professionals that further testing and treatment may be necessary.

Because CRP increases in cases of inflammation, the test is requested when acute inflammation is a risk (such as from an infection after surgery, or other trauma) or suspected based on patient symptoms. It is also requested to help diagnose and monitor treatment of chronic inflammatory conditions, such as rheumatoid arthritis and lupus. The test may be repeated often to learn whether treatment of an inflammatory disease is effective since CRP levels drop as inflammation subsides.

A high or increasing amount of CRP in your blood suggests that you have an acute infection or inflammation - most infections and inflammations result in CRP levels above 10 mg/L.

If the CRP level in your blood drops, it means that you are getting better and inflammation is being reduced.

NOTE: A standard reference range is not usually available on this site for tests. Because reference values are dependent on many factors, including patient age, gender, sample population, and test method, numeric test results have different meanings in different laboratories. Your laboratory report should include the specific reference range for your test. Lab Tests Online AU strongly recommends that you discuss your test results with your doctor. For more information on reference ranges, please read Reference ranges and what they mean.

Another test to monitor inflammation is called the erythrocyte sedimentation rate (ESR). Both tests give similar information about the presence of inflammation. However, CRP appears and then disappears sooner than changes in the ESR. Thus, your CRP level may fall to normal if you have been treated successfully, such as for a flare-up of arthritis, but your ESR may still be abnormal for a while longer.