Laboratory tests are only a supplementary means for doctors to diagnose the disease. In clinical practice, a comprehensive judgment must be made by combining the symptoms described by the patient and the abnormalities found during physical examination. For patients with heart failure, the following tests should be mandatory ECG: The most commonly used, in addition to heart rate, can diagnose whether heart failure patients have combined arrhythmias, because heart failure patients are often accompanied by premature beats, atrial fibrillation and other arrhythmias; ECG can also determine whether patients have myocardial infarction, the site of occurrence and whether the infarction is recent or old; in addition, patients with myocardial hypertrophy, pericardial effusion and other conditions ECG will also have abnormal findings. Chest X-ray: i.e. chest X-ray, the size and shape of the heart shadow can provide reference for the diagnosis of the cause of heart disease, and the degree of heart enlargement and dynamic changes can also indirectly reflect the functional status of the heart. In heart failure, the lungs are bruised and will show different degrees of alteration through chest X-ray. In addition, the presence or absence of fluid in the chest cavity and thickening of the lobe spaces are also visible. Echocardiography: It is a non-invasive test to evaluate the size of the inner chambers of the heart, the thickness of the ventricular walls and the presence of abnormalities in motion, the structure of the heart valves and the pumping function of the heart, and is the most important test for the diagnosis of heart failure. Blood brain natriuretic peptide: BNP and NT-proBNP are commonly used clinically, and their levels help in the diagnosis of heart failure. When BNP levels are normal in untreated individuals, the diagnosis of heart failure can be basically excluded. In addition, tests such as myocardial nuclear scan, coronary angiography and exercise test can understand the blood supply to the heart.