1.IntroductionPostnasal drip syndrome is a syndrome in which secretions flow backwards into the postnasal and pharyngeal areas, or even backflow into the vocal cords or trachea due to nasal diseases, resulting in coughing as or in patients with allergic rhinitis in which inflammatory secretions in the nose can flow through the postnasal orifice and pharynx or be inhaled into the lungs, the main manifestation of the syndrome.2.DiagnosisIn particular, the unconscious flow of inflammatory secretions in the nose into the airway during sleep in the supine position is most likely an allergic rhinitis developing into asthma (especially nocturnal asthma) is an important cause. The change in breathing pattern is also one of the factors that lead to a close relationship between allergic rhinitis and asthma. Swelling of the nasal mucosa, enlargement of the turbinates and retention of secretions can lead to nasal congestion, forcing the patient to change from predominantly nasal to predominantly oral breathing, so that allergens can avoid the nasal mucosal barrier and enter the lower airways directly and cause asthma. Postnasal drip syndrome is the most common cause of chronic cough in adults and the second most common cause of chronic cough in children. Postnasal drip syndrome is easily missed and misdiagnosed clinically, mainly because physicians lack knowledge of postnasal drip syndrome, pay attention only to the tonsils, pharynx and lung manifestations, and diagnose interstitial pneumonia when they see thick and deep texture on chest radiographs, ignoring the patient’s medical history and other signs. In fact, postnasal drip syndrome is the most common cause of chronic cough, and patients with chronic cough can be given specific empirical treatment for postnasal drip syndrome until the cause is determined and the disease is diagnosed based on the outcome.3. Clinical manifestations The typical clinical manifestations of patients with postnasal drip syndrome are: a. Paroxysmal or persistent cough, mainly during the day, and less after sleep. Most patients have postnasal discharge, oral mucus, itchy pharynx, foreign body sensation or the feeling of “paste sticking to the throat”, and frequent throat clearing. Simply put, the backflow of nasal secretions causes discomfort in the throat, which naturally leads to a reflexive cough. Third, there are symptoms such as nasal itching, nasal congestion, runny nose and sneezing. IV. Some patients will also have hoarseness, and even speaking will induce a cough. V. There is a history of rhinitis, sinusitis, nasal polyps or chronic pharyngitis.4. Western medical treatment for patients suspected of postnasal drip syndrome should be based on specific treatment of their possible underlying disease. For postnasal drip syndrome caused by common cold, non-allergic rhinitis, vasodilatory rhinitis, chronic rhinitis, etc., 1st generation antihistamines and decongestants are preferred. The majority of patients develop efficacy within a few days to 2 weeks after initial treatment. In postnasal drip syndrome caused by allergic rhinitis, various antihistamines are effective, and 2nd generation antihistamines without sedative effects are preferred. Nasal inhalation of glucocorticoids is also the drug of choice for allergic rhinitis. Improvement of the environment and avoidance of allergenic stimuli are effective measures to control allergic rhinitis. Allergen immunotherapy may be effective, but it takes a long time to take effect. The main treatment for acute sinusitis is the application of antibacterial drugs, but in case of poor results or high secretion, nasal inhalation of glucocorticoids and decongestants can be used to reduce inflammation. For chronic sinusitis, the following primary treatment protocols are generally used: 3 weeks of antibacterial drugs effective against gram-positive, gram-negative and anaerobic bacteria; 3 weeks of oral antihistamines and decongestants of the first generation; 1 week of nasal decongestants; and 3 months of nasal inhalation of glucocorticoids. Negative pressure drainage, puncture drainage, or surgical procedures are feasible when medical treatment is not effective. The actual nasal sinus surgery is a kind of surgery in line with the physiology of the nasal cavity and sinuses, through the reconstruction of the nasal cavity and sinus ventilation and drainage, to promote the recovery of the physiological function of the diseased mucosa so as to achieve the purpose of treating chronic sinusitis. 5, Chinese medicine treatment and for all patients with post-nasal drip syndrome, Chinese medicine is particularly important to participate in the treatment at the same time, often receiving twice the result with half the effort. For patients who are prone to colds and are triggered by climate change, the evidence belongs to the Qi deficiency is not solid. The treatment is to benefit the qi and consolidate the surface, and harmonize the ying and yang. If the cough phlegm is thin and large, the treatment is to dry dampness and dissolve phlegm; if the patient has repeated attacks of sinusitis and the flow of yellow thick mucus is obvious, the treatment is to clear heat and dampness, dissolve phlegm and open the orifice. 6, disease prevention and control in the treatment, first of all, the treatment of the cause, such as nasal polyps, acute and chronic rhinitis, sinusitis, allergic rhinitis and other primary diseases for targeted treatment, the application of anti-allergy, anti-inflammatory drugs to reduce the inflammatory response, reduce secretions; secondly is symptomatic treatment, local drops and spray nasal spray; at the same time, it can also reduce postnasal drip by promoting the recovery of mucosal function and promoting the discharge of nasal secretions. In addition, attention should be paid to diet and sleep, and combined with immunotherapy and other comprehensive therapies. For postnasal drip syndrome caused by sinusitis, nasal polyps and adenoid hypertrophy, surgical treatment should be considered. The incidence of postnasal drip syndrome is high in children under 10 years of age, such as and allergic people or suffer from chronic rhinitis, sinusitis, nasal polyps, etc. are more likely to suffer from the syndrome, especially in the weather changes when the symptoms are more obvious and more serious. Therefore Ji’an, experts recommend that the prevention and control of postnasal drip syndrome should start with the prevention of rhinitis, sinusitis, etc. at the source. If you suffer from acute inflammation, treat it promptly and do not let it become chronic. If some children have chronic rhinitis and sinusitis symptoms such as perennial runny nose, nasal congestion and sneezing, it is especially important to draw the attention of parents.