Lu Quan, Department of Respiratory Medicine, Children’s Hospital of Shanghai Jiaotong University Cough is one of the most common complaints in children attending pediatric internal medicine departments at all levels, and chronic cough, which is the only or main symptom and persistent, is often a difficult treatment problem that is not well recognized by physicians. The cough reflex is a physiological reflex that allows the body to clear excessive secretions from the throat and lower respiratory tract, remove inhaled harmful particles and foreign bodies, etc. Shahn notes that a healthy child of an average age of 10 years can have 10 coughs in 1 d (up to 34), mostly during the day, and the number of coughs per day increases once a respiratory infection is present. A healthy preschooler can have 5-7 respiratory infections per year, and if each lasts 7-9 d, he may have 50 d of coughing in a year. This indicates that coughing is a very common symptom and moreover a normal defense reflex of the organism. However, excessive, violent and frequent coughing is detrimental to the child, such as the dense bleeding spots around the face and orbits caused by pertussis, which is only superficial. Violent coughing can raise the intrathoracic pressure to +40~+75 mm Hg (1 mmHg=0.133 kPa), causing a sudden decrease in venous blood return and a sudden increase in venous pressure in the body circulation; it may cause cardiac arrhythmias, temporary cerebral ischemia It may cause cardiac arrhythmia, temporary cerebral ischemia, cough syncope, headache, or worse, pneumothorax, gastroesophageal reflux, rupture of the rectus abdominis muscle, rib fracture, hernia, etc. It may worsen the underlying pulmonary disorders, such as the spread of pulmonary infections (including tuberculosis) and the reactivation of pulmonary hemorrhagic foci. This cough is something that clinicians need to be concerned about and treat aggressively. Chronic cough is a symptom that is misdiagnosed as “upper respiratory tract infection”, “bronchitis” or even “pneumonia” in pediatric clinical practice, and various antibacterial drugs and glucocorticoids are used extensively. A large number of antibacterial drugs, glucocorticoids, etc., and, of course, phlegm-suppressing drugs are used to relieve cough. The confusion in diagnosis and the blindness in treatment are obvious, as if cough is a disease and it is “unbearable” not to use some medicine. The Editorial Board of the Chinese Journal of Pediatrics and the Respiratory Group of the Pediatric Branch of the Chinese Medical Association recently developed the Guidelines for the Diagnosis and Treatment of Chronic Cough in Children (hereinafter referred to as the Guidelines), aiming to further improve the understanding, diagnosis, differential diagnosis and treatment of this common symptom among pediatric clinicians and to standardize the rational examination and use of medications. First of all, the definition and diagnostic criteria of chronic cough in children have not been uniform in the domestic and international literature so far, which directly affects clinical judgment and diagnosis and treatment, and even more so the summary, analysis and comparison of data with each other. The Guidelines clarify that the time frame criterion for chronic cough in children is >4 weeks, which is consistent with the criteria for children indicated by the American College of Chest Physicians (ACCP). The Guidelines also describe the common causes and characteristics of chronic cough in children and provide principle advice on its treatment. Irwin and Madison have studied chronic cough systematically for a long time and proposed the use of the anatomical pathway of the cough reflex as a diagnostic clue and idea as early as 1981, which was revised in 2000 and extended to the 2006 ACCP evidence-based guidelines for the diagnosis and management of chronic cough. This view has been extended to the 2006 ACCP evidence-based clinical practice guidelines on the diagnosis and management of chronic cough. The anatomical pathway diagnostic approach adheres to a step-by-step approach to exclude or affirm one by one, without missing anything, and has greatly improved the diagnosis of chronic cough in adults, with a 90% probability of a definite etiology. However, this diagnostic approach is not fully applicable to children and does not yield the same diagnostic results. This suggests that the etiology of chronic cough in children has its own characteristics, such as congenital bronchopulmonary dysplasia and adenoid hypertrophy, which are not present in adults; the probability of various respiratory infections and post-infection cough, upper airway cough syndrome (UACS) is higher in children than in adults; and chronic cough caused by gastroesophageal reflux is relatively less common in children than in The number of children with chronic cough due to GERD is relatively lower than that of adults. Children are dynamically developing and the etiology of chronic cough varies significantly by age, which increases the complexity and individuality of diagnosis and management. In children, environmental factors are an important cause of chronic cough, for example, clinicians are not sufficiently aware of the dangers of passive smoking in the home. All of these factors point to the fact that chronic cough in children has its own characteristics and that children are not a microcosm of adults. The differences in etiology inevitably lead to differences in therapeutics, and the response of children to commonly used cough and phlegm-suppressing drugs is different from that of adults, and the use of central cough suppressants such as codeine and antihistamine sedatives such as promethazine in children with chronic cough is strictly limited. The development of guidelines for the diagnosis and treatment of chronic cough in children in China requires our own corresponding epidemiological, clinical, laboratory and therapeutic data; the development of guidelines today requires even more evidence-based level of grading, and the pediatric community lags significantly behind the adult respiratory community in these aspects, and we still lack survey data from prospective multicenter, large-sample epidemiological studies of chronic cough in children, much less basic research data, but we However, we should not stop there and recognize these deficiencies in order to go deeper in the future. The Guidelines published in this issue attempt to analyze the etiology of chronic cough in children from an evidence-based medical standpoint as much as possible, the similarities and differences among children of different ages, and, more valuable, the time frame criteria and diagnostic procedures for chronic cough in children, which are practical for pediatric practice. Chronic cough is still a symptom and the focus is on diagnosis and differential diagnosis. With a clear diagnosis, perhaps the treatment of chronic cough of different etiologies can be solved. Chronic cough is not the end of the diagnosis, it should be and can only be the starting point of its etiological diagnosis. I hope that the Guidelines will be a little enlightening and instructive to pediatric clinicians in this regard.