C-reactive protein (CRP) in serum/plasma

Why Is This Test Done?

Your healthcare provider may order this test to check for signs of inflammation, monitor conditions like arthritis, heart disease, or infections, or evaluate responses to treatments. It can also be used to screen for certain diseases or assess risk factors for conditions like cardiovascular disease.

What Does a High or Low Level Mean?

Elevated CRP levels often indicate inflammation, which can be caused by infections, injuries, autoimmune diseases, or other health issues. Lower-than-normal levels may suggest reduced inflammation, but they don’t always mean you’re healthy. Always discuss results with your provider.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure CRP levels. No special preparation is needed, but fasting may be advised depending on your provider’s instructions.

What Are Common Causes of Abnormal Results?

High CRP levels can result from infections (like pneumonia or urinary tract infections), autoimmune diseases (like rheumatoid arthritis), heart disease, or other inflammatory conditions. Low levels may occur with certain medications or in people with very low inflammation, but this isn’t always indicative of health status alone.