Chronic cough is defined as a cough of more than 4 weeks and is divided into atopic and non-atopic coughs. An atopic cough is a cough accompanied by other symptoms or signs that suggest an atopic cause, i.e. the cough is a symptom of one of these clearly diagnosed diseases, e.g. a cough with a low fever in the afternoon should be considered as tuberculosis. Cough with hemoptysis suggests bronchiectasis. Non-specific cough is defined as cough as the main or only manifestation. Chronic cough without significant abnormalities on chest radiographs. The clinical diagnosis of the cause of chronic cough is a process, and non-specificity indicates that no disease can be found to which the cough can be attributed, and this failure is likely to be temporary. Chronic cough needs to be alerted to those diseases: 1. Cough variant croup: It is the most common cause of chronic cough in children, especially in preschool and school-age children. It is usually a dry cough, often occurring at night and/or early in the morning, aggravated by exercise and cold air, with no clinical signs of infection or ineffective after prolonged antimicrobial therapy; significant relief of cough symptoms with diagnostic treatment with bronchodilators; normal pulmonary ventilation and bronchial excitation tests suggesting airway hyperresponsiveness; and a history of allergic disease, as well as a positive family history of allergic disease. A positive allergen test may assist in the diagnosis. (There are no relevant tests available in our city). 2. Upper airway cough syndrome: common in preschool and school-age children. Various rhinitis, sinusitis, chronic pharyngitis, palatine tonsil and/or proliferative hypertrophy, nasal polyps and other upper airway diseases may cause chronic cough. The cough is accompanied by white foamy sputum (allergic rhinitis) or yellow-green pus sputum (sinusitis), and is worse in the morning or with changes in position, accompanied by nasal congestion, runny nose, dry throat with foreign body sensation and repeated clearing of the throat; the follicles in the posterior pharyngeal wall are markedly hyperplastic, sometimes with cobblestone-like changes, or with mucus-like or purulent secretions; antihistamines (paracetamol, loratadine, cetirizine, secundin), leukotriene receptor antagonists (montelukast) and nasal glucocorticoids are effective for chronic cough caused by allergic rhinitis, and chronic cough caused by purulent sinusitis requires antibacterial medication for 2-4 weeks; nasopharyngoscopy or lateral head and neck films, sinus x-ray or CT films may help in the diagnosis. 3. Post-infectious cough: a common cause of chronic cough in young children and preschoolers with a recent clear history of respiratory tract infection; an irritating dry cough or with a little white mucous sputum; chest X-ray examination without abnormalities or only showing increased texture in both lungs; normal pulmonary ventilation or showing a transient airway hyperresponsiveness; cough is usually self-limiting. 4. Gastroesophageal reflux cough: 24-hour lower esophageal pH monitoring is the gold standard for the diagnosis of GERC, but it is difficult to perform this operation; the best time to develop paroxysmal cough is at night; the cough can also intensify after eating with a positive 24-hour lower esophageal pH monitoring. (We are unable to perform relevant tests in our city and can only do so based on clinical symptoms). 5. Psychogenic cough: Common in school-age and adolescent children, more common in older children; predominantly daytime cough, disappearing when focused on an event or resting at night; may be a high-pitched cough like a goose; often accompanied by anxiety symptoms, but not organic disease. 6. Allergic cough: clinically certain children with chronic cough have atopic constitution and effective treatment with antihistamines and glucocorticoids, but they are not bronchial asthma or cough variant asthma. They have an irritating dry cough; normal pulmonary ventilation and negative bronchial excitation test; increased sensitivity of cough receptors; history of other allergic diseases, positive allergen skin test, and elevated total and/or specific serum IgE. 7. Foreign body inhalation: Foreign body inhalation is an important cause of chronic cough in children, especially those 1-3 years old. Other symptoms include decreased breath sounds and wheezing, and there may be a history of asphyxia. The cough usually presents as a paroxysmal violent choking cough, or it may only present as a chronic cough with obstructive emphysema or pulmonary atelectasis, and once the foreign body enters below the small bronchus, there can be no cough. 8, respiratory infections caused by specific pathogens: a variety of pathogenic microorganisms such as pertussis, tuberculosis, mycoplasma, etc. 9, pulmonary iron-containing xanthophyllosis: long-term cough, with hemoptysis, anemia, etc. Sputum smear Prussian blue staining can be seen in the cells with blue particles, which are iron-containing xanthophyll particles, according to which a clear diagnosis can be made. When a child is suspected of having a chronic cough, it is important, as a family member, to give a detailed account of the development of the disease and the corresponding symptoms, so as to facilitate the doctor’s judgment, perform some comprehensive and necessary tests, follow up regularly, and develop an individualized plan.