Respiratory tract infections are the most common and top of the list of pediatric diseases. Common symptoms include: fever, cough, sputum, runny nose, sneezing, sore throat, itchy throat, hoarseness, headache, dizziness; may be accompanied by nausea, vomiting, abdominal pain, diarrhea, etc. The doctor may diagnose rhinitis, pharyngitis, herpes pharyngitis, tonsillitis, purulent tonsillitis, laryngitis, tracheitis, bronchitis, asthmatic bronchitis, pneumonia, etc. based on what is seen on physical examination. Sometimes they are collectively referred to as: respiratory infections. Some children have multiple respiratory infections a year, so the concept of recurrent respiratory infections is introduced; defined as: recurrent respiratory infections refer to the number of upper and lower respiratory infections occurring too frequently within a year, beyond the normal range; because children are in the process of growth and development, the respiratory system and immune system is not yet well developed, resistance to pathogens invasion, resistance to disease is weak, 3-4 times in a year respiratory infections It is common, too many respiratory infections are pathological. Narrow, funnel-shaped, soft cartilage, mucosa rich in blood vessels and lymphoid tissue, prone to laryngeal obstruction after laryngitis; 4, lower respiratory tract: relatively narrow, rich in blood vessels, mucous membrane cilia, mucus cilia function is not strong, airway elastic tissue is underdeveloped, alveolar alveolar cavity and the amount of underdeveloped respiratory muscle. Pediatric respiratory defense function is also relatively poor, due to: 1, organic factors: the anatomical and physiological characteristics of the pediatric respiratory tract and immune function is underdeveloped, especially in infants and young children; the number of T cells, poor function, low phagocytosis, lysozyme, lactoferrin, complement, interferon and other substances in respiratory secretions that can resist pathogens are low; 2, disease factors: weak children, malnutrition, especially En, Fe deficiency and rickets, congenital diseases, etc., more prone to recurrent respiratory infections and difficult to heal; 3, environmental factors: climate change, environmental pollution, passive smoking, pets, indoor decoration, etc. are prone to recurrent respiratory infections. How to prevent recurrent respiratory tract infections? 1. Find the causative factors and treat them accordingly. For chronic lesions in the nasopharynx, ask the ENT department to assist in the diagnosis and treatment. Since most upper respiratory tract infections are viral, antibiotics should not be misused. 2. Doctors and health care providers should keep parents fully informed of the disease. 3. Pay attention to nutrition and dietary habits as well as guidance on strengthening physical fitness. 4.Cultivate good hygiene habits and prevent cross-infection. 5.Good family care, pay attention to the symptoms of the change of the disease. 6, if necessary, give targeted immunomodulators: such as clinically used: bacterial extracts (Panfosu); chemical agents (Pidomod); Chinese herbal medicine (Sophora Qiao Huang, Yu Ping Feng San); trace elements (iron, zinc) and so on.