Asthma is divided into allergic asthma and non-allergic asthma, allergic asthma is very much, and its triggering factors are as follows: 1, the most important is related to various allergens in life, such as atmospheric pollution, PM2.5, dust, pollen, all kinds of flutter, and sometimes because of home decoration, change the new curtains. Of course the most common household allergen is dust mite, many patients are allergic to dust mite, but there are some patients are food allergies, such as some patients have asthma after eating seafood; 2, more common is respiratory infection, many patients after a cold or bronchitis, induced asthma symptoms, frequent asthma patients feel very deep, once the cold or respiratory infection, will come to the clinic in time, because patients know that timely consultation Some people work harder and stay up late, which may trigger asthma in some patients due to plant nerve dysfunction, especially vagus nerve hyperactivity; 4, mental factors, some people are particularly nervous or angry, and this kind of excessive emotion sometimes triggers asthma. So sometimes on TV, you can see some children or adults, after arguing with others, will have asthma symptoms. Then some people take an envelope and breathe into it, because then there may be hyperventilation, which may also trigger asthma. Of course there are some other factors.