C-Reactive Protein (CRP) Test

Reviewed

Measures the level of C-reactive protein (CRP) in your blood to detect inflammation in the body.

Preparation and collection

Tell your provider about any supplements or medicines you take, including magnesium and NSAIDs like ibuprofen and aspirin. Do not stop taking any prescription medicines without talking to your provider first.

Understanding this test

Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.

  • The test measures inflammation but does not identify its cause or location.
  • Certain medicines, supplements, and lifestyle factors can affect CRP levels.
  • Normal CRP levels do not rule out all inflammatory conditions.

What to do next

Your provider will interpret your CRP results along with other tests, your symptoms, and medical history to determine the cause of inflammation and guide treatment.

Evidence source

U.S. National Library of Medicine: C-Reactive Protein (CRP) Test

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