Frequent breathlessness and feeling difficult to breathe may be caused by the following reasons: First, consider obstruction in the airway, commonly chronic obstructive pulmonary disease, for patients with a long history of smoking, and repeated coughing and coughing, and the above symptoms will appear whenever the season changes, it is necessary to improve the lung function test to clarify whether it is chronic obstructive pulmonary disease. Second, often feel out of breath, dyspnea, also need to exclude bronchial asthma, cough variant asthma and other episodic diseases, to improve the bronchial excitation test. Third, frequent breathlessness and dyspnea also need to exclude heart failure and other cardiac causes. Fourth, if the frequent breathlessness and dyspnea also need to consider whether the lung occupancy, bronchial occupancy lesions, it is best to improve the chest CT, fiber bronchoscopy to clarify the diagnosis.