Cough is the most common symptom in the respiratory department. Many people visit the doctor because of chest pain, stomach pain, urinary incontinence, insomnia at night and other reasons caused by coughing. Many cough patients may not be able to detect the problem, but they have used all kinds of drugs, some of which can reduce it but cannot cure it completely. As a doctor, I was also tormented by cough twice. I also used medication for a month and had a CT examination for fear of any problem, and then gradually got better by taking Luo Han Guo in water. Coughs can be divided into acute, subacute and chronic coughs according to their duration. Acute coughs are those that last less than 3 weeks, chronic coughs are those that last longer than 8 weeks, and subacute coughs are those that last between 3 and 8 weeks. The coughs we mention here are mainly subacute and chronic coughs. Among the subacute and chronic coughs, the most common etiologies confirmed by domestic and international studies are upper airway cough syndrome, cough variant asthma, gastroesophageal reflux and eosinophilic bronchitis. UACS used to be called postnasal drip syndrome (PNDS) because these patients often have rhinosinusitis, with postnasal drip, frequent throat clearing, posterior pharyngeal mucus adherence, and pebble-like signs on the pharyngeal wall as typical manifestations; chronic cough caused by this nasal disease is called PNDS. There are no strict diagnostic criteria for this type of disease, which involves a variety of underlying diseases, no specific clinical symptoms and signs, and no specific test results. The degree of inconsistency is such that UACS is currently used instead of PNDS to cover all upper respiratory tract diseases associated with cough, with the disadvantage that the diagnostic criteria are more difficult to grasp. Some patients are often very worried about abnormalities in the lungs because of cough. Sometimes we prescribe a chest radiograph that always states that the lung texture is increased and thickened, and the conclusion states that bronchitis is possible, but in fact these coughs do not occur from the lungs. The severity of the cough is closely related to the distribution and sensitivity of the cough receptors. Cough receptors are widely distributed, and cough receptors from the pharynx, trachea, bronchi, lungs, and pleura are stimulated to enter the cough center through the glossopharyngeal and vagal afferent pathways, which then send impulses to act on the corresponding respiratory muscle groups via the vagus nerve to produce a series of muscle contraction movements. Although cough receptors lack specificity, the laryngeal and tracheal receptors are the most sensitive and are sensitive to both chemical stimuli (e.g., smoke, poison gas) and mechanical stimuli (e.g., pulling), while other receptors are sensitive only to mechanical stimuli. When receptors at these sites are stimulated, they are then transmitted to the center via the vagus nerve, where they are integrated in the cough center and stimulate the submucosal glands to secrete mucus and increase the clearance of airway secretions. In addition to the abundance of receptors in the pharynx, the mechanism of cough triggering in the upper airway cough syndrome is often due to the flow of nasal or sinus secretions into the hypopharynx or larynx that excite the receptors in these areas. Of course, patients presenting with upper airway cough syndrome have a more sensitive cough reflex than the general population and are more likely to be directly excited by various physical or chemical irritants. The cough is mostly accompanied by coughing sputum, mainly during the day, and many patients will have a postnasal drip of influenza, for example, they often report a suctioning motion; in addition there is throat clearing, pharyngeal itching, nasal congestion, and runny nose. Some patients also have sore throat and hoarseness. Physical examination may reveal a discharge from the nasal cavity in the posterior pharyngeal wall and a pebble-like appearance of the pharyngeal mucosa, although please note that this is also found in patients with cough of other etiologies and is not specific. According to our Cough Guidelines, the proposed diagnostic criteria are: (1) episodic or persistent cough, predominantly during the day and less often after sleep; (2) postnasal drip and or a sense of mucus attachment to the posterior pharyngeal wall; (3) history of rhinitis, sinusitis, nasal polyps or chronic pharyngitis; (4) examination reveals mucus attachment and pebble-like view of the posterior pharyngeal wall; and (5) relief of cough after targeted treatment. Well, after the diagnosis, let’s talk about the treatment. As we said above, UACS is a syndrome with multiple underlying diseases, so its treatment is different according to different etiologies. Next, I will give a few examples to illustrate each. Case 1, an 18-year-old male, came to the clinic with a week-long cough. After taking a medical history, we learned that the patient had perennial nasal congestion, clear runny nose and sneeze finding, all mistakenly treated as a cold, and recently the appeal symptoms reappeared with a significant cough. Take much unsatisfactory. I diagnosed allergic rhinitis and gave budesonide nasal spray, montelukast and Huifenesin oral solution after the patient’s symptoms improved significantly after three days. This case is a cough caused by allergic rhinitis, which is very common in clinical practice and is often treated as a cold by patients and their families. “This is when we have to pay attention to the fact that it is normal for everyone to have a cold two or three times a year, but more than five times to pay attention to other diseases. Typical allergic rhinitis is usually easy to diagnose clinically, i.e. sneezing, runny nose, nasal congestion, accompanied by extra-nasal manifestations such as itchy eyes and itchy ears. The currently advocated treatment for this type of nose is firstly to avoid exposure to various allergens, followed by long-term treatment with nasal hormones, supplemented by anti-allergic drugs and leukotriene antagonists. Cough can be treated with drugs containing anti-allergic agents and central weak cough suppressants. Case 2, a 30-year-old female, presented to the clinic with a 20-day history of cough and yellow sputum, complaining of pharyngeal discomfort, and on examination, secretions were found adhering to the posterior pharyngeal wall. The patient was treated with Genoton, amoxicillin clavulanic acid and guaifenesin, and the symptoms improved significantly after one week. In this case, the cough was caused by chronic sinusitis. The clinical manifestations of this disease include nasal congestion, runny nose, headache, dizziness, cough, and pus-producing sputum. The causes of cough caused by acute and chronic sinusitis include irritation of the pharynx due to a large amount of pus flowing into the pharynx, and also due to inflammation of the nasopharynx. Treatment of course begins with anti-infective therapy, including cephalosporin antibiotics, amoxicillin clavulanic acid, mucus pro-discharge agents including Genoton, eucalyptus lemon pie capsules, supplemented with licorice combination or Huifei Xuan. Case 3, a 40-year-old male with no history of smoking, had a two-week cough with pharyngeal itching. Pulmonary CT and routine blood and IgE were normal. The itchy pharynx was more pronounced and worse at night, and various cough suppressants (licorice combination, strong lozenges) were not effective. Pulmonary function and bronchial excitation tests were normal. The patient was considered to have an allergic cough and was given loratadine anti-allergy medication and advised to take Luo Han Guo drink. Some of them have a history of cold, which may be due to airway inflammation and damage to the epithelial mucosa of the airways, and the exposure of subepithelial nerve endings to physical and chemical stimuli, leading to increased release of neuropeptides. On the one hand, it leads to or exacerbates neurogenic inflammation of the airway, sensitizing peripheral cough receptors, and on the other hand, it causes a downregulation of the cough threshold by amplifying the nerve impulse signals from sensory nerve endings to the brain; in short, an increase in sensitivity. This condition is self-limiting by having a self-limiting effect, except that the duration varies greatly from person to person. Antihistamines and central cough suppressants are preferred as medications, and patients with severe coughing can try inhaling Echolal.