Heart failure is heart failure. The three main indicators are ejection fraction, 6-minute walk test, and brain natriuretic peptide. The normal values are as follows. 1. Ejection fraction: Ejection fraction is the ejection of blood during cardiac contraction examined by cardiac ultrasound, which is an important indicator to determine the severity of heart failure. Under normal circumstances, the ejection fraction of the left ventricle is greater than or equal to 50%, and that of the right ventricle is greater than or equal to 40. When the result is less than normal, heart failure is considered. 2. 6-minute walk test: a method of determining heart failure by measuring the distance traveled after six minutes of brisk walking in a corridor at the patient’s tolerance level. If the walking distance is between 426 and 550 meters, it indicates mild heart failure; if it is between 150 and 425 meters, it indicates moderate heart failure; if the walking distance is less than 150 meters, it is considered to have severe heart failure. 3. Brain natriuretic peptide: Brain natriuretic peptide is a hormone produced by cardiomyocytes, which can regulate blood pressure, body fluids and sodium balance. It is normally 0 to 100 pg/ml, and when the result is elevated and accompanied by symptoms such as dyspnea, chest tightness, shortness of breath, etc., the occurrence of heart failure is considered. Patients with heart failure should go to the hospital in time and be treated under the guidance of a doctor to avoid delaying their condition.