C-reactive protein (CRP) – Serum

Why Is This Test Done?

Doctors may order CRP tests to check for signs of inflammation, monitor chronic conditions (like arthritis or heart disease), or evaluate how your body is responding to an illness or treatment. It can also help assess risk for certain conditions before symptoms appear.

What Does a High CRP Level Mean?

Elevated CRP levels often indicate inflammation, which can be caused by infections (like pneumonia or urinary tract infections), autoimmune diseases (like lupus or rheumatoid arthritis), or other health issues such as heart disease or cancer. However, CRP alone doesn’t diagnose a specific condition—it’s usually one piece of a larger picture.

What Does a Low CRP Level Mean?

Low CRP levels typically suggest little to no inflammation in your body. This can be normal if you’re healthy, but it may also indicate that an infection or other inflammatory condition is under control or absent.

How Is This Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab, where it’s analyzed to measure CRP levels using a sensitive immunoassay method. Results are usually available within 24 hours.