The voice is a natural musical instrument that we are born with, a miracle given by creation, and it has evolved and improved during the evolution of human beings. The voice is a natural instrument that needs to be taken care of, otherwise it will become unpleasant or even unusable. Do you know what factors can damage the voice? I believe every friend will give some answers, such as excessive use of voice, improper vocal method, long-term smoking, frequent drinking, spicy diet, lack of sleep, low water consumption, air pollution. Yes, all of the above factors will cause more or less damage to the voice, which we try to avoid by caring for our voice. In addition, there is another factor that is not well known to the public, or even outside the scope of common knowledge, which can be said to be an invisible destroyer of the voice, and that is pharyngeal reflux. People must ask, what is pharyngeal reflux? This question is a hot topic that has been concerned and talked about by the medical community in recent years. Recently, a symposium was organized by the Chinese Medical Association’s Otolaryngology-Head and Neck Surgery Branch and the editorial board of the Chinese Journal of Otolaryngology-Head and Neck Surgery, in which more than two dozen experts from China got together to discuss the diagnosis and treatment of pharyngeal reflux disease and reached a preliminary consensus. I also participated in this meeting. In this meeting, the definition of pharyngeal reflux and laryngeal reflux disease was described as follows: pharyngeal reflux disease (LPRD) is a general term for the reflux of gastric contents into the upper esophageal sphincter above, causing a series of symptoms and signs, with clinical manifestations such as hoarseness (or dysphonia), pain in the throat, foreign body sensation in the throat, persistent throat clearing, chronic long-term cough, dyspnea, laryngospasm, and This is a medical professional definition, which may not be easy to understand for the general reader. No matter, let’s explain it in layman’s terms. As you know, food has to be chewed by the teeth, swallowed by the pharynx, and then formed into a food mass in the esophagus, which reaches the stomach with the peristaltic movement of the esophagus. The food is ground up in the stomach and mixed well with gastric juice to form chyme. The stomach has a powerful digestive function because it secretes a large amount of gastric juice, the main components of which are gastric acid, pepsinogen, mucus and internal factors. Gastric acid is produced by the main cells of the stomach wall and the main component is hydrochloric acid (HCL). Gastric acid is bactericidal and activates pepsinogen, which is activated and converted into pepsin, which is used to digest proteins. The presence of gastric acid makes the gastric juice very acidic with a pH value between 1.5 and 2.0. Under normal conditions, the stomach lining is not damaged by gastric acid because it secretes alkaline substances to neutralize the acid and protect the mucous membrane of the stomach lining. Gastric acid and pepsin, which have important digestive functions, become destructive molecules once they get off their turf and reflux into the esophagus and pharynx. However, the resistance of the esophagus and the pharynx to stomach acid is different. The esophageal mucosa has the ability to secrete alkaline substances and has a mucosal barrier that neutralizes some of the gastric acid, and thus any esophageal reflux that occurs 50 times a day falls into the physiological category. The pharynx has a weak protective mechanism against gastric acid and pepsin, and reflux more than 3 times a day with a PH of 4-5 can cause damage to the mucosa. In addition to the two main components of gastric acid and pepsin, alkaline substances such as bile and pancreatic juice are also involved in the pathogenesis of pharyngeal reflux. So, how do the stomach contents break free and escape to places where they shouldn’t go? In fact, our organism has designed mechanisms to prevent reflux of gastric contents, in short there are two hurdles, the upper and lower esophageal dilators. These two muscles are located at the upper and lower ends of the esophagus. When food goes down, the sphincter is open and food passes, and when no food passes the sphincter is in contraction, making a high pressure zone at the upper and lower ends of the esophagus, preventing the reflux of gastric contents. When some factors cause the dysfunction of the upper and lower esophageal sphincter, it is equivalent to the relaxation of these two lines of defense, two “naughty ghosts” stomach acid and pepsin into the pharynx, will produce a series of symptoms and signs. Factors that cause relaxation of the esophageal sphincter include the following: (1) Food and beverages: tomatoes or their processed products; carbonated beverages; chocolate; mint; citrus; caffeine; spicy foods, etc. (2) Irrational and inappropriate dieting (3) Long-term physical or psychological stress (4) Long-term smoking (5) Negative chest pressure due to obstructive sleep apnea, etc. Gastric acid and pepsin can directly cause damage to the pharyngeal mucosa, for example, pepsin can digest and break down intercellular junction structures and directly enter the cells and damage them. Pepsin can also cause a decrease in carbonic anhydrase in the pharyngeal mucosa. Carbonic anhydrase catalyzes CO2 to produce bicarbonate, which neutralizes gastric acid, and a decrease in carbonic anhydrase makes the pharyngeal mucosa less effective at neutralizing gastric acid. Throat reflux brings a series of symptoms, but they are mostly nonspecific, meaning that they are not specific to pharyngeal reflux disease and can occur in other throat disorders as well. The most common symptom is hoarseness, which is characterized by intermittent, sometimes fatigued voice, and is often treated as “laryngitis”, which occurs several times a year and lasts from a few days to a few weeks each time. In addition, the common symptom is excessive mucus in the throat and the urge to clear the throat, which accounts for about 50% of cases. Other symptoms and their probability of occurrence are: chronic cough 51%, foreign body sensation in the throat 47%, heartburn and/or acid reflux are uncommon and account for only 10-30%. Some patients have mild to moderate dysphagia as their first symptom, and some even have more severe dysphagia. Other symptoms include laryngospasm, acoustic prominence granuloma, etc. Some studies have shown that laryngeal and subglottic stenosis and laryngeal cancer are also associated with pharyngeal reflux. There are so many symptoms of laryngeal reflux, how to initially determine if you have laryngeal reflux? Clinically, we have a symptom scale, and you can score yourself according to the scale. The reflux symptom scale is as follows: Reflux Symptom Index Scale The effects of pharyngeal reflux are also manifested on laryngoscopy. Common manifestations include mucosal erythema of the vocal folds, with patchy mucosal congestion in the posterior part of the vocal folds in less severe cases, and multiple scattered mucosal erythema visible in the laryngeal cavity in more severe cases. In addition, there are different degrees of edema of the vocal folds, mucosal hyperplasia and hypertrophy of the posterior larynx, granuloma of the vocal folds, shallowing or disappearance of the laryngeal chambers, and mucosal edema of the lower edge of the vocal folds forming a pseudo-vocal fold groove. A professional doctor will make a preliminary diagnosis based on the symptoms and the laryngoscopic presentation. In laryngoscopic manifestations of reflux laryngitis, mucosal erythema is seen in the vocal prominence. Posterior joint mucosal hypertrophy and shallow laryngeal chambers Since there are so many uncomfortable symptoms and dangers of laryngeal reflux, how to prevent and treat it. The first and the most basic point is lifestyle change. Since the disease is closely related to the digestive tract, treatment should also start with changing dietary habits. Unsuitable foods include citrus fruits such as lemons, limes, and oranges, and beverages such as coffee, strong tea, carbonated drinks, chocolate, and alcohol consumption. What kind of diet is healthy? It can be summarized as low-fat, low-acid, acid-base balanced, sugar-free, grain-free, and dairy-free diet. Specifically, such as low-fat milk; fruits including apples, peaches, pears, bananas, and berries; low-fat meats, such as chicken and fish; and a small intake of fat and a small amount of sweets. Lifestyle treatment also includes elevating the head at bedtime (when there is nocturnal reflux), eating small, frequent meals, avoiding food 3 hours before going to bed, not overfeeding, not lying down immediately after meals, and wearing less tight clothing. For mild cases of pharyngeal reflux, lifestyle changes can achieve a therapeutic effect. If the treatment effect is not achieved, medication should be used under the guidance of a doctor. There are two types of drugs commonly used, one is antacid drugs, that is, to reduce the secretion of stomach acid, and the other is gastric motility drugs, that is, to promote gastrointestinal motility. Antacids are the mainstay of treatment for pharyngeal reflux and also include two types: H2 receptor blockers, which reduce gastric acid secretion by selectively inhibiting H2 receptors on the stomach wall, such as ranitidine and famotidine; and proton pump inhibitors (PPI), which inhibit the final link of gastric acid secretion, the proton pump H-K-ATPase. Such as omeprazole, esomeprazole, rabeprazole, etc. The effect of proton pump inhibitors is stronger than that of H2 receptor blockers. The timing and dosage of these drugs should be under the guidance of a physician. In conclusion, pharyngeal reflux disease is a common disease and one of the causes of voice disorders. The research, understanding and discussion of this disease is still going on in the medical community. We hope this text will help you to have a basic understanding of this invisible destroyer of the voice, avoid bad habits that may lead to throat reflux, and protect our wonderful natural instrument, the voice.