Bronchial asthma is an allergic disease that most people develop at a young age or in their youth, and attacks occur in the spring and fall or when it is cold. Asthma attacks come and go quickly and are characterized by expiratory difficulties; after the asthma stops, it is like a normal person. However, if repeated attacks cannot be relieved, it may develop into emphysema and pulmonary heart disease. In asthmatic bronchitis, in addition to the symptoms of chronic bronchitis: coughing and coughing for a long time, the patient also has significant wheezing, which is aggravated by respiratory infections. The disease usually develops in the cold season, and the middle-aged and elderly people are the majority. If this disease is not well controlled, it often develops into emphysema and pulmonary heart disease in the late stage. Bronchial lung cancer can also cause wheezing when the cancer blocked the large bronchial tubes. Patients feel difficulty when exhaling and inhaling. All of these types of asthma are caused by diseases of the bronchi or lungs and are called pulmonary asthma. Another type of asthma is caused by heart disease and is called cardiogenic asthma. Patients usually have coronary heart disease, rheumatic heart disease, cardiomyopathy or hypertension and develop left heart failure, which causes stasis of blood and impaired gas exchange in the lungs and the onset of asthma. This type of wheezing often strikes at night, most often with sudden onset of dyspnea 1 or 2 hours after falling asleep. The patient wakes up suddenly due to chest tightness and breathlessness and is forced to sit up and gasp for air, cough and cough pink foamy sputum. Most patients sit up and the wheezing subsides, a process called nocturnal paroxysmal dyspnea. In addition, there is a kind of occupational asthma, which means that asthma is related to certain occupations, such as exposure to certain chemical or metal compounds at work, causing asthma. Their main characteristic is that contact with a specific substance or being in certain specific environments can cause an attack of the disease, and once the exposure is removed, the symptoms disappear.