C-reactive protein (CRP) concentration, serum/plasma

Why This Test Might Be Ordered

Your doctor may order a CRP test to check for signs of inflammation, monitor conditions like infections, autoimmune diseases, or heart disease, or evaluate how well you’re responding to treatment for these conditions. It can also be used to screen for certain health risks or to monitor chronic conditions over time.

How the Test Works

A small blood sample is taken from a vein in your arm. The blood is then sent to a lab, where it’s analyzed to measure the amount of CRP present. CRP levels are compared to a reference range to determine if they’re within normal limits or if further action is needed.

What to Expect Before the Test

You can eat and drink normally before the test, as it doesn’t require fasting. Wear comfortable clothing with an easy-to-reach sleeve if you’re having the blood drawn. If you’re on blood-thinning medication or have a bleeding disorder, let your doctor know beforehand.

What to Expect During the Test

The blood draw is quick and usually painless. You may feel a slight pinch or sting when the needle is inserted, but most people tolerate it well. Afterward, you might experience a small bruise or swelling at the site, which usually goes away within a day or two.