Patient: “Doctor, I have a cough with a lot of phlegm, often accompanied by shortness of breath, especially after activity, and I even feel that I can’t catch my breath and have a feeling of being out of breath.” Doctor: “When did the above symptoms appear?” Patient: “About a week ago.” Doctor: “And do you usually have a cough?” Patient: “Usually, it’s fine.” DOCTOR: “No cough at all?” Patient: “No, usually there is a cough.” DOCTOR: “Then why didn’t you see a doctor earlier?” Patient: “That’s a normal cough, it’s not necessary.” The above is a frequent conversation between a doctor and a patient in a daily respiratory specialist’s clinic. We can see that what patients mean by “normal cough” is a cough and phlegm that they usually have, but because they have it every day, they don’t think about it and often ignore it. Most of these so-called “normal coughs” are seen in the early morning when we wake up, because after coughing for a while and coughing up phlegm, the cough is reduced and becomes normal, or even easier than normal, so we get used to it after a long time, so we call it a “normal cough”. It is important to emphasize here that coughing is not normal. The essence of coughing is a self-protective action of the respiratory tract, through which secretions or foreign bodies can be discharged from the respiratory tract to keep it open and clean. There are many microscopic cilia on the surface of the lining of the human respiratory tract, which constantly oscillate toward the oropharynx to sweep away dust, microorganisms and foreign bodies inhaled into the respiratory tract. If inflammation occurs in the respiratory tract, such as upper respiratory tract infection, bronchitis, pneumonia, etc., secretions, bacteria, viruses and dead white blood cells mix together to form phlegm, which is sent by the cilia of the respiratory tract to the mucous membrane of the trachea for accumulation, thus triggering a nerve impulse that is transmitted to the center and causes coughing and coughing up of phlegm. A “normal cough” means that you have a mild or severe inflammation of the respiratory system, especially in the early stages of chronic bronchitis, when the cough is more pronounced in the early morning, or when you cough up more pus in the morning. If no intervention is made in this state, it may lead to further aggravation of respiratory diseases and complications, such as obstructive emphysema, pulmonary heart disease, respiratory failure, etc., which not only bring great pain to patients, but also make treatment very difficult and consume excessive medical resources. In clinical practice, it is found that most people with a “normal cough” have a history of smoking and often cough after smoking, which is uncomfortable, but is as little as the pleasure of smoking. In clinical practice, doctors also found that the longer they smoked, the more they smoked, the less sensitive they were to coughing, and these people did not cough until they couldn’t breathe. Therefore, doctors recommend that people with a “normal cough” should seek treatment or consult a doctor as soon as possible to nip the so-called “normal cough” in the bud, because the respiratory tract has a strong ability to repair itself and some early inflammatory reactions in the airways can be reversed. However, if the extent of the lesion exceeds the airway’s ability to repair it, the best doctors and medications will not be able to help. If our airways are constantly damaged, and the air quality is often poor, as the saying goes, “a man’s life is a breath of air”, to use a modern phrase: how can we be embarrassed?