The pharynx is connected to the nasal cavity above and the esophagus and trachea below, and is the common channel for breathing and digestion. It has important physiological functions such as breathing, swallowing, speech formation, defense and protection, and immunity, which are directly related to survival and affect the quality of life. People often use the term “throat” to describe the important position and role of the throat in the human body. At the same time, the pharynx is an important channel for the body to communicate with the outside world and exchange gases and food. In summary, the anatomical and physiological characteristics of the pharynx are “connecting up and down, communicating inside and outside, common channel”. Therefore, the pharynx is easily affected by changes in the external environment and diseases of neighboring organs, as well as by the immune function and defense ability of the body. The combined effect of these factors makes the incidence of pharyngeal diseases high, and to a certain extent reflects the overall functional status of the human body. Chronic pharyngitis is the most common disease of the pharynx. However, the diagnosis of chronic pharyngitis currently lacks uniform criteria and is highly arbitrary. Chronic pharyngitis refers to diffuse chronic inflammation of the pharyngeal mucosa, submucosa, and lymphatic tissue. It is classified as simple, hypertrophic, or atrophic. Many local and systemic lesions can present with symptoms of pharyngeal discomfort, so careful screening is needed to avoid misdiagnosis and missed diagnoses. The main differential diagnoses of chronic pharyngitis are discussed. (A) Reflux pharyngitis Reflux pharyngitis (LPR) is a disease caused by reflux of gastric contents into the pharynx; the pathogenesis is mainly due to the dysfunction of the upper and lower esophageal sphincters and the weakened contouring ability of the esophagus, which causes gastric contents to reflux into the pharynx and cause injury. The main cause of damage to the pharynx from gastric contents is direct damage to the mucosa by gastric acid and pepsin. In addition, stimulation of the larynx, vagal reflex, bronchoconstriction, coughing and repeated throat clearing also damage the laryngeal mucosa. There are no accurate statistics on the incidence of reflux laryngitis, but it accounts for a significant proportion of patients with throat discomfort, and its incidence has been underestimated due to lack of awareness of the disease. The most common symptoms of reflux pharyngitis are hoarseness and dysphonia, others are chronic cough, foreign body sensation in the throat, habitual throat clearing, difficulty in swallowing, and only a few patients have heartburn and acid reflux. Uncommon symptoms include: laryngospasm, arytenoid cartilage fixation, laryngeal stenosis and tumors, and acoustic prominence granuloma. The most typical signs on fiberoptic laryngoscopy are posterior joint edema and erythema. In addition, there are pseudo-vocal sulci, laryngeal ventricular occlusion, erythema and congestion of the laryngeal mucosa, vocal fold edema, posterior joint hypertrophy, diffuse laryngeal edema, granuloma, and laryngeal mucosal thickening. The evaluation method of symptoms and signs has been proposed and is now accepted and recognized. The Reflux Symptom Index (RSI) is used for symptom evaluation and is shown in the following table: Table 1. How much have the following symptoms affected you in the past month? (0=no effect, 5=very severe) 1. hoarseness or voice problems 2. need to clear throat 3. heavy throat discharge or post-nasal discharge 4. difficulty swallowing food, water or pills 5. coughing after meals or after lying down 6. difficulty breathing or breath whistling 7. incurable cough 8. foreign body sensation in throat 9. heartburn, chest pain or indigestion