I. Etiology: 1, the result of repeated attacks or prolonged acute laryngitis. 2, excessive use of voice, improper vocalization, common in teachers, actors, singers, women workers in yarn mills, or not necessarily professional vocalists, too strong or too much use of voice, constant and continuous speech, too high, too long singing. 3, inhalation of harmful gases such as industrial gases, smoking, chemical dust can make the vocal cords thicken. 4.Infection of the nose, sinuses and pharynx is also a source of chronic irritation of the larynx. 5, the lower respiratory tract infection of purulent secretions and pharynx long-term contact, but also prone to chronic laryngitis. The main symptoms are as follows: 1. Hoarseness is the most important symptom. The voice becomes low and coarse in the morning, and then gradually improves with increased activity and coughing up laryngeal secretions, and then becomes worse in the next morning; hoarseness is reduced after abstinence, and the symptoms are aggravated by more speech, which is intermittent. It becomes persistent over time. 2.Increased secretion in the larynx, often feeling that there is sputum adhering to it, and whenever you speak, you must cough to remove the sticky sputum. 3. Dryness of the throat and soreness of the throat when speaking. Treatment: 1. Remove stimulating factors, quit smoking and drinking. Pay attention to proper rest of vocal cords and reduce vocalization. Prohibit loud shouting and correct the method of pronunciation. Actively treat nasal, pharyngeal and lower respiratory tract infections, so that the respiratory tract is clear and the secretions from neighboring organs are less likely to stimulate the larynx. 2.Apply nebulized inhalation method as appropriate to inject anti-inflammatory and anti-swelling drugs such as amiloride and chymotrypsin and dexamethasone into the nebulizer, and the patient contains the ejector of the nebulizer by mouth and connects to oxygen or high-pressure air pump to make the drug atomized. Take deep breaths continuously to make the nebulized medicine inhaled into the throat. Once a day, each course of treatment 6 times, can be 2-3 courses of treatment. 3. Use Huang’s sound pills, clear sound pills and other Chinese medicines. Disease prevention: 1, timely treatment of acute laryngitis, to prevent the evolution of chronic. 2, to prevent excessive use of voice, teachers, literary workers should pay attention to the correct vocal method, especially during the cold. 3, strengthen labor protection, the production process of harmful gases, dust, etc. need to be properly handled.