When the left lung is removed in its entirety, it may result in decreased endurance for human activity, decreased lung function, and in severe cases, symptoms such as dyspnea and chest tightness. When the left lung is completely removed due to disease, only the right lobe of the lung carries out respiratory action, and the effective area of lung tissue for gas exchange is reduced by half. However, the right lung can compensate appropriately. When the right lung tissue just meets the body’s oxygen demand, there can be no obvious hypoxia symptoms, and there will be no chest tightness, shortness of breath. However, when the organism carries out activities and emotional excitement, the oxygen demand of the organism increases in a short period of time, and there is a possibility that the right lung tissues can not compensate for it, and then symptoms of hypoxia can appear. There is a decrease in lung function and a significant decrease in activity endurance. When the left lung is resected and serious symptoms appear, it is recommended to seek timely medical treatment and standardize the treatment.