The normal value of b-type brain natriuretic peptide precursor is less than 100 pg/mL, which increases with age, and the normal range for people over the age of 75 years should be less than 450 pg/mL. b-type brain natriuretic peptide is a biologically active polypeptide similar in function and structure to cardiac natriuretic peptide, and is widely distributed in tissues such as the heart, lungs, and brain, with the heart having the highest content. When heart failure occurs, changes in ventricular volume load and ventricular wall tension can stimulate the secretion of B-type brain natriuretic peptide, producing natriuretic peptide effects, regulating blood pressure and dilating blood vessels, and reducing cardiac load. Elevated b-type brain natriuretic peptide precursors primarily reflect heart failure. The ventricular wall is overstressed and the ventricular muscle secretes endogenous protective hormones, i.e. b-type brain natriuretic peptide precursor. The worse the cardiac function, the more brain natriuretic peptide is secreted, and the more b-type brain natriuretic peptide precursors there will be. The b-type brain natriuretic peptide precursor reflects the severity of heart failure and is an indispensable clinical indicator for the diagnosis of heart failure. If it is higher than 400pg/mL and deviates from the normal value, it should be treated promptly and reviewed regularly.