What is a CRP Test?

C-reactive protein or CRP test is occasionally used to diagnose or confirm presence of certain types of inflammation or to assess how treatment for inflammation is progressing. This is a simple blood test that can usually be drawn at a lab or sometimes in a doctor’s office, via the normal method of needle aspiration of blood from the middle of the arm. There are actually two CRP test types: the average test or a higher sensitivity test that is sometimes used to look for evidence of heart disease.

When the body has inflammation of different types it may produce a higher level of C-reactive protein. Some conditions associated with elevated CRP include diseases where the bowel is inflamed, autoimmune disease, pelvic inflammatory disease and certain forms of arthritis. As part of other diagnostics, a doctor that suspects one of these conditions could order a CRP test to determine if this protein is elevated.

Elevated levels of c-reactive protein aren’t necessarily enough to diagnose a condition alone. Combined with other tests, they might indicate presence of an illness. Alternately a positive test could confirm results of other testing and examination.

More often these conditions are already diagnosed, but since inflammation levels may not always be physically notable, doctors can use the CRP test to determine if a condition is worsening or improving. For instance, when a person takes prednisone for illnesses like lupus, it’s hard to say if inflammation is worsening or improving, and inflammation could attack just about any area of the body without the patient or doctor knowing. By checking c-reactive protein, extensive scans of a whole body aren’t necessary, unless there is clear indication of a problem.

The high sensitivity CRP test has specific applications in cardiac medicine. People who seem otherwise healthy may sometimes indicate that they have underlying heart problems with very miniscule elevations of CRP in the blood. An hsCRP test could be a means of ruling out heart failure. Some doctors order this test as part of medical screenings, especially associated with preventative care. Should the test come back with elevated CRP, doctors could suggest additional exams to rule out heart disease.

The CRP test isn’t always perfect. Sometimes the human body has higher CRP levels than would be deemed normal. A person who is overweight is likely to have elevated c-reactive protein even if he is perfectly healthy with no inflammatory conditions and no heart disease. In ordering either test, such factors might be taken into account.