Insufficient breathlessness may be caused by chronic bronchitis, pneumothorax, pulmonary heart disease and other diseases. 1. Chronic bronchitis: it is a common chronic inflammatory disease, with typical symptoms such as shortness of breath and chest tightness, mostly occurring in the elderly. If combined with respiratory infections, the bronchial mucosa is congested and produces edema, and phlegm obstructs the bronchial lumen, you will have the symptom of breathlessness. 2. Pneumothorax: due to some reasons, the lungs are ruptured, gas enters the pleural cavity and causes accumulation of air, and the air pressure causes the lungs to contract, resulting in insufficient oxygen and the symptoms of dyspnea and breathlessness. 3. Pulmonary heart disease: its typical symptoms are chest tightness and dyspnea. Increased pulmonary vascular resistance, pulmonary arterial pressure increases the right heart dilatation and hypertrophy, resulting in patients with symptoms of breathlessness. Breathlessness can also be seen in asthma and other diseases, it is recommended to go to the hospital to clarify the cause of the disease, under the guidance of the doctor for treatment.