Cardiac insufficiency can be divided into left cardiac insufficiency and right cardiac insufficiency. Left cardiac insufficiency is mainly characterized by dyspnea and right dyspnea is mainly characterized by venous stasis. 1. Left heart insufficiency: it is usually caused by the decline of left ventricular systolic and diastolic functions, and often manifests as dyspnea after activity, nocturnal paroxysmal dyspnea, sedentary respiration, coughing up pink foamy sputum and other dyspnea symptoms, and it may also have symptoms of malaise, fatigue, cyanosis and so on. 2. Right heart insufficiency: it is mainly due to the stagnation of blood in the body circulation, which leads to the change of the function of each organ or even failure, and may have the symptoms of peripheral venous stagnation such as loss of appetite, abdominal distension, blood in stool, jugular vein filling, hepatomegaly, double lower limb edema, ascites and so on. If the above types of dyspnea or long-term bilateral lower extremity edema occurs, it is necessary to consult a doctor in a timely manner to clarify the cause of the disease and treat it as soon as possible in order to avoid delaying the condition.