bnp, brain natriuretic peptide, can assist in the diagnosis and identification of heart failure and can assess the degree of failure. Bnp is a class of peptides with potent natriuretic, diuretic, vasodilator, and antihypertensive effects, and its secretion can be increased by ventricular volume expansion and pressure loading; therefore, measurement of bnp in the blood pressure can be used for the diagnosis and evaluation of heart failure. Clinically, bnp testing is performed in patients with dyspnea, heart failure, and acute coronary syndromes. When bnp is below 100pg/ml, heart failure can be ruled out. When bnp exceeds 400pg/ml, the probability is that the patient is suffering from heart failure, such as bnp in 100~400pg/ml, in addition to heart failure, there may also be pulmonary embolism, right heart failure, and so on. If the bnp exceeds 100pg/ml, please conduct further examination and treatment according to the doctor’s advice to avoid delaying the condition.