Heart failure, or heart failure, is a diagnosis that requires a combination of history, symptoms, signs, and ancillary tests. Heart failure is a group of syndromes in which various structural or functional heart diseases lead to insufficient cardiac output, resulting in insufficient blood perfusion to organs and tissues. It includes left heart failure, right heart failure, total heart failure, and can also be categorized into acute heart failure and chronic heart failure. The diagnosis is based on the evidence of pre-existing underlying heart disease manifested as body circulation stasis or pulmonary circulation stasis. For example, left heart failure presents with varying degrees of dyspnea and pulmonary rales, and right heart failure presents with jugular vein signs, hepatomegaly, and edema. The presence of gallop rhythm and valvular zone murmurs on cardiac auscultation is also important in the diagnosis of heart failure. Cardiac ultrasound can assess the cardiac ejection fraction and to some extent cardiac function, which can help in the diagnosis of heart failure. Brain natriuretic peptide (BNP) results are also important in the diagnosis of heart failure. When heart failure occurs, it is recommended to seek timely medical treatment and standardize the treatment under the guidance of professional doctors.