The diagnostic criteria of chronic heart failure include medical history, clinical manifestations, laboratory tests and echocardiography, etc. Based on the results of the tests, the clinical diagnosis will be made by the doctor. 1. Medical history: The diagnosis of chronic heart failure is based on whether the patient has a history of coronary artery disease, hypertension, myocarditis, congenital heart disease, diabetes mellitus, systemic lupus erythematosus, and so on. 2. Clinical manifestations: patients with chronic heart failure usually have symptoms such as dyspnea, coughing up sputum, hemoptysis, edema, cyanosis, etc. They also have signs such as irregular pulse beat, elevated blood pressure, wet rales in the lungs, and jugular vein distension. 3. Laboratory tests: Elevated B-type natriuretic peptide (BNP) and amino-terminal brain natriuretic peptide precursor (NT-proBNP) are usually diagnostic and can be used to assess the severity of heart failure. Myocardial damage can be assessed on the basis of troponin. 4. Echocardiography: Echocardiography reveals the structure and function of the heart, which in turn clarifies the severity and possible causes of heart failure.