The causes of bronchial asthma are actually not very clear at present, but current research shows that bronchial asthma is mainly caused by genetic and environmental factors. Genetic factors are relatively easier to understand, meaning if parents have a history of bronchial asthma, then their children, grandchildren, and other blood relatives may have a higher chance of developing bronchial asthma than the general population. Additionally, bronchial asthma is also related to environmental factors, such as air pollution, smoking, dust mites, pollen, etc.