Ask the doctor: Should my CRP level change from test to test?

Ask the doctor

Should my CRP level change from test to test?

Q. I had a blood test for CRP that came back at 1.9, which my doctor said was on the high side. I had it checked again a few weeks later and it was under 1. What does this mean? Should I have it checked again?

A. Your liver makes C-reactive protein CRP in response to inflammation. Doctors have used it for years to monitor diseases with a lot of inflammation, such as pneumonia, rheumatoid arthritis, and lupus. Thanks to supersensitive tests for CRP developed in the early 1990s, doctors can now detect lower levels of the protein that might indicate the kind of subtle, chronic inflammation that reflects unhealthy changes in artery walls.

Results of this high-sensitivity CRP (hsCRP) test can vary a bit from test to test. Over the long term, though, large trials show that hsCRP levels are about as stable as blood pressure and total cholesterol.

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