Cigarette smoking (including second-hand smoke and third-hand smoke) is a strong trigger for asthma patients, which is more harmful than the general abnormal gas caused. Cigarette smoke exists in about 4,000 kinds of chemical components, smoking can cause asthma because the components in cigarettes can stimulate the vagus nerve to cause bronchospasm, bronchial epithelial hyperplasia and mutation, resulting in narrowing of the lumen, airflow limitation, airway resistance increases, leading to acute asthma attacks or exacerbations. Smoking can also increase the insensitivity of asthma patients to corticosteroid therapy and weaken its anti-inflammatory effect. Therefore, smoking is closely related to asthma. Usually, children whose parents smoke are more likely to develop asthma than those whose parents don’t smoke, and children who grow up living with second- and third-hand smoke have chronic cough, phlegm and other symptoms of asthma more often. If a pregnant woman is exposed to cigarettes for more than 8 hours a day, the chances of having a child with asthma increases twofold. Compared to non-smokers, smokers have higher asthma morbidity and mortality rates, more severe wheezing symptoms, require more medication, and have a poorer quality of life. For your health and the health of others, please quit smoking as soon as possible.