The common causes of dyspnea are as follows: 1. Respiratory system diseases: The respiratory system is a major site for gas exchange, including pulmonary ventilation and pulmonary ventilation, so basically all bronchial and pulmonary diseases can cause dyspnea. For example, the most common are chronic airway diseases, such as chronic obstructive pulmonary disease, bronchial asthma, acute or chronic bronchitis, etc. The second also includes bronchial lung tissue lesions such as bronchial dilatation and lung cancer; 2. Cardiovascular diseases: After oxygen enters the blood, the body’s circulatory system is also needed to transport oxygen to all parts of the body. Therefore, the state of the heart function, the condition of the circulatory system, is also directly related to the respiratory distress can be relieved; 3, blood system diseases: because the transport and transit of oxygen in the body is mainly through the combination with hemoglobin to complete, so the blood system diseases lead to a decline in hemoglobin, and then anemia will cause respiratory distress; 4, neurological diseases: such as central problems, because the respiratory center of the brainstem lesions, and then cause respiratory distress; 5, neurological diseases: such as central problems, because the brainstem respiratory center lesions. 5, mental factors: for example, people in the exam tension, or emotional tension, can appear dyspnea, this dyspnea is often caused by psychological reasons. Therefore, the different causes of dyspnea should be dealt with accordingly, so as to improve dyspnea.