1.Spring is warm and cold at first, with a lot of sand and wind, a large temperature difference between day and night, and sometimes cold air stimulation, all of which can induce asthma. In this climate, the content and flow of allergens in the air increases significantly, so the prevention of asthma needs to adapt to climate change. 2.Infection factors. Respiratory infections increase significantly in spring, and the pathogens are mostly viruses, bacteria, mycoplasma, etc. These pathogens as allergens inhaled by people can directly induce asthma, but also can destroy the closely linked epithelial cells, so that they widen, and other external allergens to take advantage of the situation. Some statistics show that a viral infection takes 6-8 weeks to repair, and obviously the chances of an asthma attack increase during these 6-8 weeks. If you repeatedly catch a cold, asthma attacks are one after another, and even the months are connected. 3, spring outdoor activities and sports correspondingly increased, the amount of activity, so that due to breathing when inhaling the number of allergens and the opportunity to increase accordingly, asthma will be prone to attacks. 4, Spring flowering season, pollen flying in the air, and the number of outdoor mold in Beijing increases in spring, and children’s outdoor activities increase at this time, children with latent symptoms of asthma inhale air containing pollen or mold pollution, they will be allergic to the disease.