In the clinic, we often encounter some “old faces” who get sick every month or even every 1-2 weeks, with fever, cough, runny nose and other cold manifestations, and in severe cases, shortness of breath. The parents are tired of it, and have run to many hospitals and clinics, seen many experts and professors, and even various prescriptions and herbs, and eaten all kinds of drugs and health supplements to improve resistance, but there is no improvement. In clinical practice, children with truly low immunity are rare, and the cause can usually be found after several infections, such as temporary hypogammaglobulinemia, and regular supplementation of propecia will have a significant effect. The vast majority of recurrent respiratory infections, on the other hand, are actually due to allergies. This is something that many parents and even pediatricians do not correctly recognize. The allergy mentioned here refers to the allergy of the entire respiratory tract, including the nasal, sinus and bronchial allergies. Due to the continuous allergic state, the mucosa of the respiratory tract is vulnerable to pathogenic invasion and completely defenseless, and a slight infection can develop and produce a series of respiratory tract infection manifestations, and the treatment, in addition to symptomatic treatment and antiviral and antibacterial, also In addition to symptomatic management and antiviral and antibacterial treatment, it is necessary to strengthen anti-allergy treatment and to supplement vitamin A to repair the respiratory mucosa. Some other recurrent respiratory infections are in fact already asthma. A significant proportion of children usually do not present clinically as wheezing, but as recurrent “colds” or upper respiratory tract infections, but each time they can progress to lower respiratory tract infections, recurrent bronchitis, capillary bronchitis, and pneumonia, lasting 10 days or more, with ordinary anti-inflammatory therapy being ineffective, but responding well to wheezing medications or nebulizer therapy. Most chronic or recurrent bronchitis is asthma; asthma is the most common underlying lesion in recurrent pneumonia.