The level of N-terminal brain natriuretic peptide precursor, NT-pro BNP, is correlated with age, and the level of NT-pro BNP increases naturally with age. NT-pro BNP is mainly synthesized and secreted by ventricular myocytes and can be used to reflect changes in ventricular function, and its level increases with age. In terms of diagnostic cutoffs for acute heart failure, the diagnostic cutoff for patients younger than 50 years old is 450 pg/ml; for patients 50-75 years old, the diagnostic cutoff is 900 pg/ml; and for patients older than 75 years old, the diagnostic cutoff is 1,800 pg/ml. In addition to age, the normal level of NT-pro BNP is also affected by many other factors such as renal clearance, gender, and body weight. Therefore, the normal level cannot be judged by the age condition alone.