C-reactive protein (CRP)

CRP · C-reactive protein test · inflammation blood test · high-sensitivity CRP

A blood test from a vein. It shows if there is inflammation in your body and how strong it is.

For fever, a suspected infection, joint pain, or to check how treatment works. High-sensitivity CRP is sometimes ordered to check the risk of heart disease.

⏱ Duration: the blood draw takes 2 to 3 minutes; results usually in 1 day

Be sure to tell your doctor

If you were recently ill, injured, or had surgery
Which medicines you take, especially hormones and anti-inflammatory medicines
Pregnancy

How to prepare

Food. The test is usually done in the morning on an empty stomach, or 3 to 4 hours after a light meal. Check with your clinic.
The day before. No fatty food, alcohol, or hard workouts.
Water. You can drink plain water.

What to bring

Your referral, if you have one
Past CRP results, to compare

How it goes

You sit down and rest your arm on a support
A band is tightened above your elbow
The skin is wiped with alcohol
Blood is taken into a tube with a needle
A cotton pad is pressed on the spot

What you'll feel

A quick prick
If you are scared or feel dizzy, say so. You can lie down

Afterwards

Keep the cotton pad pressed for 3 to 5 minutes
You can eat right away
Your doctor will explain the result. The number alone is not a diagnosis

Common questions

What does a high CRP mean?

It means there is inflammation in your body. The doctor looks for the cause. It may be a cold, an infection, or something else.

How is CRP different from ESR?

CRP rises faster and falls faster. That is why it is easier to track inflammation with it.