BNP is a protein substance secreted from the heart ventricles in response to increases in blood pressure or dilation of the ventricles that occurs when heart failure worsens. BNP can be measured from a simple blood test. BNP blood levels increase when heart failure symptoms worsen and decrease when the heart failure condition is stable.
The BNP level in a person with heart failure—even someone whose condition is stable—is higher than in a person with normal heart function. BNP can be used to distinguish causes of shortness of breath in CHF patients that may also have asthma, emphysema, or pneumonia.
Victoria’s comment: After having CHF for 7 years, my doctor started ordering this blood test. I asked why he ordered a test to find out if I had CHF when he already knew that I had it. He says it helps him to tell if my medication is working well to control the CHF.