The earliest symptoms of left heart insufficiency are palpitations, dyspnea, hepatosplenomegaly, puffiness, shortness of breath, and venous anger. As the patient’s condition worsens, these symptoms become more and more severe and have a higher chance of occurring at night, which will be relieved with proper rest. As the condition of patients with left heart insufficiency progresses, the patient’s discomfort will gradually worsen, even to the point of difficulty in whistling and inability to lie down. Due to the reduction of antegrade blood discharge, the patient will also develop shortness of breath, panic, dizziness, weakness of the limbs and other general conditions. In severe cases, ascites, peritoneal effusion, bilateral lower limb edema, abdominal distention, and hepatosplenomegaly may occur. The causes of left heart insufficiency are also extremely complex, including cardiac stress, immune disorders, incorrect lifestyle habits, genetic causes, and so on. The treatment and prevention of the disease need to start from the cause, which is more relevant. Before diagnosing the disease, it is necessary not only to clarify the cause of the disease, but also to fully understand the results of the patient’s examinations. If the patient is diagnosed with left heart insufficiency, the most timely treatment is needed, and the majority of patients are treated with medication, including cardiotonic drugs, diuretics and vasodilators. The amount of medication should be taken according to the doctor’s advice, and the medication should be taken on time to get good results. Patients with left heart insufficiency must change their lifestyles during the treatment of the disease, quit smoking and drinking, while obese patients need to reduce their weight and exercise properly. Patients with hypertension need to pay close attention to the changes in blood pressure, control the diet and pay attention to more rest in order to have a good treatment effect.