OVERVIEW
What is the BNP lab test?
BNP or Brain Natriuretic Peptide is a protein which is made continually by blood vessels and heart in small quantities. But its release can increase if the heart senses that it needs to work hard. In such a case heart muscle is stretched and works hard to pump blood in normal resting condition. This test is indicated for measuring BNP levels in blood.
Why is BNP lab test done?
The test is done:
- As it aids in detection and evaluation of heart failure (heart still pumps blood but has difficulty in doing so)
- As BNP test can detect heart failure in 80% of the cases
- If you have heart failure or symptoms like shortness of breath(SOB), coughing or wheezing, fatigue, swelling in abdomen/legs and/or feet
- Loss of appetite or nausea
- As test will also help in showing how badly has heart failure worsened
- As it helps in deciding which treatment to give to the patient or if hospitalization is required
- As it helps monitoring if the treatment with medications is working properly or not.
- What BNP level indicates heart failure?
Any result going above 100 pg/mL is considered abnormal and shows increased likelihood & severity of heart failure.
- Is it possible that BNP is elevated without heart failure?
If such a case happens, an additional investigation on cardiac structure & function needs to be done.
- What can cause the BNP level to be high?
It may be caused by intrinsic heart dysfunction, or due to secondary causes like pulmonary (lung) or kidney diseases.
- Which signs show that the heart is failing?
Signs like having SOB, weakness & fatigue, swelling in ankles/feet/legs, reduced ability to exercise, and rapid/irregular heartbeat.
- What is considered bad BNP level?
Patients having greater than 81 pg/mL BNP are likely to have recurrent MI (myocardial infarction) or progressive heart failure.
INTERPRETATION OF THE RESULTS:
- Normal range of BNP: less than 100 picograms per milliliter (pg/ml)
- High level of BNP: above 400 pg/ml
However, depending upon age and gender, normal BNP levels can be:
- < 45 years old: In men is 35 pg/ml or below; and in women is 64 pg/ml or below
- 46–60 years old: In men is 36–52 pg/ml; and in women is 46–60 pg/ml
- 61–82 years old: In men is 53–91 pg/ml; and in women is 96–163 pg/ml
- 83 or older: In men is 93 pg/ml or below; and in women is 167 pg/ml or below
You get tested for detecting and evaluating a heart failure.