I. What is asthma? In general, asthma is a chronic inflammatory disease of the respiratory tract. The greater the degree of inflammation in the airways, the more difficult it is to inhale air and exhale it from the lungs. The inflammation we are referring to here is a “metabolic inflammation”, which is tissue damage caused by the body’s immune response; it is not the usual infection-induced inflammation that requires antibiotic treatment. Swelling and inflammation of the airways are a major part of the problem, but not the whole story. During an asthma attack, the swelling of the airways increases, the lining of the airways becomes very sensitive, and the tiny muscles surrounding the airways begin to tighten. This is called “bronchospasm”. This inflammation of the airways may increase slowly over time, slowly and imperceptibly. Each asthma attack increases the inflammation in the airways and, if no anti-inflammatory measures are taken, can lead to bronchial blockage or spasm, which may even be life-threatening due to breathing difficulties. Second, asthma symptoms include 1. cough: usually occurs at night or in the morning, and sometimes continues to occur for months to years. 2. Wheezing: A high-pitched whistling sound can be heard when exhaling. 3.Shortness of breath: Feeling that there is not enough air, breathing is very difficult, and the speed of breathing increases. 4.Tightness in the chest: It feels as if something is pressing on the chest. 5.Difficulty in breathing can affect the quality of sleep. 6.Inability to participate in sports, or even affect the usual activities. You may have all or some of the above symptoms, but not all people with asthma have shortness of breath; many people only have a cough. These symptoms come and go, and they can be triggered by certain factors in the environment, exercise, upper respiratory tract infections, etc. C. What are the causes of asthma? Intrinsic and extrinsic factors. Intrinsic factors include family history and personal allergy history; extrinsic factors include triggering factors (also called trigger factors) 1. Family history and personal history (intrinsic factors): If your parents or close relatives have allergic diseases, such as: asthma, allergic rhinitis, neurodermatitis, etc., you are more likely to have asthma. Your risk of developing asthma is also increased if you have: (1) allergic rhinitis (2) Allergic skin diseases, such as eczema. 2. Triggers (external factors): Allergic triggers: Inhalation: dust mites, molds, pollen, animal dander, etc.; common food: milk, eggs, shellfish, seafood, nuts …… Non-allergic triggers: exercise, viral infections, cold air, smoke, air pollution, inhalation “Second-hand” smoke (i.e. in a smoking environment), aspirin and other medications 3. “Occupational asthma” due to exposure to certain chemicals at work.