Chronic asthmatic bronchitis is a chronic non-specific inflammation of the trachea, bronchial mucosa and surrounding tissues. It is characterized clinically by chronic coughing, coughing or wheezing and recurrent episodes. The director of Qu Weimao and we talk in detail about how asthmatic bronchitis is caused: 1. Infectious factors A variety of viral and bacterial infections can be caused. The more common ones are syncytial virus, parainfluenza virus, influenza virus, adenovirus, rhinovirus and Mycoplasma pneumoniae, etc. Some cases can be complicated by bacterial infections on top of viral infections. The trachea and bronchi of infants and young children are relatively small, and the elastic fibers around them are not well developed. The mucosa is easily swollen and congested by infection or other stimuli, causing narrowing of the ducts, and the secretions are sticky and not easy to cough out, thus producing wheezing sounds. 3, allergic factors The children mostly have allergic tendency, that is, the children or relatives have eczema, food or drug allergy, allergic rhinitis, urticaria, asthma and other allergic diseases.