Heart Failure and the BNP Blood Test

Medically Reviewed by James Beckerman, MD, FACC on November 19, 2022
2 min read

When you have heart failure, your heart makes two proteins. Your doctor will call them B-type natriuretic peptide (BNP) and N-terminal-pro-BNP (NT-pro-BNP). Levels of both in your blood go up when your heart failure gets worse and go down when it gets better.

A test called a BNP blood test measures those two important levels. It’s able to spot heart failure more than 80% of the time.

BNP levels help your doctor figure out if you have heart failure or something else that has similar symptoms such as shortness of breath. The test also shows if your heart failure has worsened. It’ll help your doctor decide what treatments you need and if you need to be hospitalized. It may also give them a look into what the future may hold. It is a sensitive test to allow the doctor to evaluate improvement or worsening of heart failure and to help monitor whether or not the medication is working well.

Depending on your medical center, you may get tested for one or both proteins.

A small amount of blood will be taken from you. Then it’s placed in a machine that reads the level of BNP and NT-pro-BNP. The test takes about 15 minutes. In some places, the blood sample needs to be sent away to a lab to be tested.

The level of BNP tends to increase as heart failure gets worse. But it can also increase with age. Testing BNP levels is one of the most sensitive ways to show how well you're doing on heart failure treatment.

Ask your doctor to explain the results of your BNP tests.