Mild heart failure may have no obvious symptoms, or it may have symptoms, with exertional dyspnea and decreased activity tolerance on the left side of the heart, and mild lower extremity edema and weakness on the right side of the heart. Mild total heart failure may have a combination of both of these heart failure symptoms. Mild heart failure generally refers to heart failure according to the cardiac function classification to reach class I, class II, some mild patients may still be able to compensate for cardiac function without obvious symptoms, some patients may have symptoms, as follows: 1. Patients with left-sided heart failure will have exertional dyspnea and decreased activity tolerance in the early stage, such as obvious chest tightness and dyspnea when climbing two or three floors of a building, and chest tightness, dyspnea, and panic when walking one kilometer on level ground. 2. Patients with right-sided heart failure have mild early symptoms, and may have lower limb edema, starting from the ankles of both lower limbs, and some may also have symptoms of fatigue. 3. The manifestations of mild total heart failure may include manifestations of both of the above conditions, or there may be no obvious symptoms. In order to clarify whether there is heart failure, it is difficult to detect it through symptoms in the early stage, and it is necessary to go to the cardiology department of the hospital to improve the laboratory tests.