Asthma is a relatively specific disease. Whether it is allergic asthma (exogenous) or non-allergic asthma (endogenous), the common pathogenesis is a chronic inflammation of the respiratory tract. This chronic inflammation is not caused by infection, it is an inflammation involving a variety of inflammatory cells, structural cells, and inflammatory mediators, mostly associated with allergic reactions. Inflammatory cells include: mast cells, eosinophils, T lymphocytes, dendritic cells, macrophages, and neutrophils. Structural cells include: airway epithelial cells, airway smooth muscle cells, endothelial cells, fibroblasts and myofibroblasts, airway nerve fibers, etc. The inflammatory mediators are: leukocyte chemokines, (cysteinyl) leukotrienes, interleukins and TNF-α, granulocyte colony-stimulating factor, and histamine nitric oxide. The pathogenesis is very complex and has not been fully elucidated. The clinical manifestations of asthma are diverse, except for the aforementioned shortness of breath, chest tightness, and sometimes simply a cough or chest pain, etc., which are still called asthma, mainly from the same pathogenesis. The development of asthma is strongly related to genetic factors and is the result of a combination of genetic and environmental factors, with some estimating that genetics accounts for roughly 80% and the environment for about 20%. Any parent with a history of asthma or allergies, such as allergic rhinitis, urticaria, eczema, etc., is a predisposing factor for asthma. Together with environmental irritants, such as environmental pollution, especially home renovation, etc. are more likely to trigger or aggravate asthma. Preliminary investigations have found that people with a family background of asthma are more than 10 times more likely to develop asthma, and the heritability of exogenous asthma is higher than that of endogenous asthma. The mode of inheritance is mainly polygenic. Adverse living environment refers to damp and crowded living place, keeping pets and flowers, recent home renovation and new furniture, using carpets and owning stuffed toys, etc., which increase the possibility of developing asthma. Current research has found that house dust mites are the most common asthma allergens. Therefore, if you have asthma at home, it is best not to smoke, not to have pets, and to regularly wash bed sheets, bedding, pillowcases and sofa seat covers and expose them to the sun. Also, the floor of your home should be cleaned thoroughly and regularly. In short, asthma manifests itself in many different ways.