C-reactive protein (CRP) in plasma by high-performance liquid chromatography (HPLC) with probe-based measurement

Your doctor may order a CRP test to check for inflammation in your body, which can help detect infections, monitor chronic conditions such as arthritis or lupus, and track how well a treatment is working over time.

Doctors may order CRP testing to monitor conditions like infections, autoimmune diseases (such as rheumatoid arthritis), or to check for signs of inflammation after surgery or injury. It can also help evaluate heart disease risk or response to treatment.

A high CRP level usually means there is inflammation somewhere in your body, which could come from an infection, an injury, or a long-term condition such as heart disease or rheumatoid arthritis, while a normal or low result generally suggests that no significant inflammation is present.

Elevated CRP levels often indicate inflammation, which can be due to infections, injuries, or certain diseases. Very high levels may suggest severe inflammation or infection. Very low levels might suggest no active inflammation, though this isn’t always reliable on its own.

A CRP test uses a small blood sample that is typically drawn from a vein in your arm, and only minimal preparation is needed, although you should tell your healthcare provider about any medications, vitamins, or supplements you are currently taking.

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate plasma, which is then sent to the lab for testing. This test uses plasma, not whole blood.

Before your CRP test, your healthcare provider will explain why the test is being done and review your medical history and current medications, and in most cases you can eat and drink normally beforehand since fasting is usually not required for this test.

No special preparation is needed for this test. You can eat and drink normally before your blood draw. If you’re on blood-thinning medication, let your healthcare provider know before the test.