This kind of patients is more common in the respiratory clinic. Many patients have symptoms of cold such as stuffy nose, runny nose, headache and fever that are significantly reduced or even gone, but keep coughing, and some patients can last for half a month, a month or even longer. Let’s first understand the structure of the respiratory system. The structure of the respiratory system is like an inverted tree, the roots of which are equivalent to the throat, the trunk is equivalent to the trachea, the branches are equivalent to the bronchi, the trachea has many gradations, from thick to thin, from large to small, in many levels, and the leaves are equivalent to the alveoli. When a person gets a cold, the inflammation goes from top to bottom. If the inflammation is in the throat, it is laryngitis; if it is in the trachea, it is tracheitis; if it is in the bronchus, it is bronchitis; if it goes down, it may be pneumonia. There are diagnostic criteria for chronic bronchitis, and the diagnosis relies primarily on history and symptoms. After excluding other heart and lung disorders (such as tuberculosis, pneumoconiosis, bronchial asthma, bronchiectasis, lung cancer, heart disease, cardiac insufficiency, etc.), the diagnosis is established when there is a chronic or recurrent cough with sputum or with wheezing that lasts for at least three months each year and for two consecutive years or more. If the onset of cough lasts for less than three months per year and there is a clear objective test (e.g. X-ray, lung function, etc.), the diagnosis can also be made. If the cough is not treated promptly and thoroughly, it can develop into chronic bronchitis. Many patients with chronic bronchitis, emphysema, and pulmonary heart disease develop this way over time, repeatedly. This kind of patient who keeps coughing belongs to the category of “cough” in Chinese medicine, and it is good to take Chinese medicine tonics to treat it.