Elevated BNP indicates heart failure, and the more severe the heart failure is, the more pronounced the BNP elevation is, which can be taken as an important factor in determining heart failure. In normal people, BNP is less than 100 pg/ml. When BNP is greater than 400 pg/ml, heart failure exists, and generally patients will have difficulty breathing or lower limb edema. When BNP is between 100-400pg/ml, some people have no symptoms and can continue to be observed. BNP measurement can also observe the effect of heart failure treatment, some people have no relief of symptoms after treatment, but BNP starts to decrease, which will bring confidence to the treatment. However, it is still important to take into account the clinical manifestations, especially the control of infections, which can lead to exacerbation of heart failure, and the presence of elevated BNP, which can easily produce thrombosis in patients with heart failure, is also a factor that can aggravate heart failure.