Gastroesophageal reflux disease (GERD) is a common clinical disorder that mostly affects middle-aged and older adults, with US epidemiological studies showing that 20% of people experience heartburn and/or acid reflux once a week and 40% once a month. These figures still underestimate the prevalence of GERD, as the increasing number of identifiable atypical presentations of GERD has not been accounted for. In addition to affecting quality of life and leading to multiple esophageal complications such as reflux esophagitis, GERD (gastroesophageal reflux) can also cause extraesophageal symptoms due to extraesophageal reflux or also known as supraesophageal reflux and pharyngeal reflux, which can lead to multiple respiratory disorders such as chronic cough, asthma, pneumonia, interstitial fibrosis, chronic bronchitis, sleep apnea, and bronchiectasis. In 1912, William Osier described the relationship between GERD and asthma, stating that “asthmatic attacks may be caused by direct irritation of the bronchial mucosa or indirectly by gastric reflux”. “In 1903, Dr. L.A. Coffin concluded that GERD was associated with laryngeal disease, and that hiccups and a hyperacidic environment caused by gas in the stomach were the main cause of symptoms in many patients with nasal tract disease. He believes that because many patients have no gastrointestinal symptoms, this problem is overlooked. A recent study confirmed their observations regarding the pathogenesis and clinical manifestations of extraesophageal disease associated with gastroesophageal reflux disease. Symptoms may result from damage to susceptible supraesophageal tissues by acidic pepsin or be mediated through the mechanism of esophageal reflux. In addition, because typical GERD symptoms such as heartburn and acid reflux are often lacking in patients with extraesophageal reflux, internists overlook the fact that GERD plays an important role in these symptoms. Even when GERD is suspected, the diagnosis can be difficult to confirm. Finally, effective treatment of GERD can significantly improve or even completely relieve extraesophageal symptoms. Asthma is common, affecting 5-10% of the world population, and its prevalence has increased worldwide over the last decades. Available epidemiological evidence has established an association between GERD and asthma, with some evidence supporting a pathogenic role and including GERD as an important causative agent of asthma. The literature clearly reflects the correlation between asthma and GERD. GERD is considered a potential trigger in patients with refractory asthma, non-allergic asthma, asthma with moderate to severe GERD, and with nocturnal exacerbations of asthma. Why can GERD cause asthma? The two main mechanisms are (1) asthma possibly due to trace aspiration of gastric reflux or (2) asthma due to vagally mediated esophagobronchial reflex mechanisms. In patients with a history of respiratory symptoms associated with GERD symptoms, 20 mg omeprazole was empirically administered twice daily. Chronic cough, i.e., a cough that persists for more than 3 to 8 weeks, is the primary symptom of drug therapy and is common in internal medicine clinics. Gastroesophageal reflux disease has been recognized as an important trigger of chronic cough for at least 30 years. Many studies have identified GERD as one of the 3 most common causes of chronic cough in all age groups, accounting for 40% of all cases.In 1981, Irwin et al. conducted a prospective study of patients with chronic cough. They were able to determine the cause of cough in all patients and improved 98% of cough patients by direct treatment. Using gastroscopy and barium esophagus, they found that gastroesophageal reflux disease accounted for 10% of the etiology, ranking 3rd after postnasal hypersecretion and asthma.Irwin et al. then added esophageal pH testing, and they concluded that GERD was the cause of chronic cough in 21% of patients.In 1996, Mello et al. also included esophageal pH testing in the evaluation of persistent stress immunoreactive in patients with cough. They concluded that GERD causes 40% of cough patients, more than any other cause. Among patients who did not smoke but had unreasonable chest radiograph findings and were not taking angiotensin-converting enzyme inhibitors, 99.4% were due to GERD, postnasal hypersecretion, and/or asthma. Exceptionally some studies have also confirmed that GERD is an important cause of cough. Explain how GERD causes cough: (1) excessive flow of reflux from the esophagus into the upper or lower airways may cause cough or (2) reflux may trigger sensory nerve receptors in the esophagus resulting in a vagal-mediated cough response. All patients with chronic cough associated with suspected GERD should first undergo their lifestyle modifications. Some authors agree with the empirical treatment of patients with symptomatic GERD and chronic cough with high doses of gastric acid suppression. However, regardless of the diagnosis of GERD causing cough, there are still no clear treatment guidelines regarding pharmacological therapy. Internal medicine studies have confirmed that small amounts of antacid therapy cause cough, thus supporting the maximum dose of antacid therapy. The association of obstructive sleep apnea syndrome (OSAS) with gastroesophageal reflux has been well studied. Gastroesophageal reflux may contribute to the development of obstructive sleep apnea syndrome, but the link may simply be common risk factors such as alcoholism and obesity. Another possibility is the abnormal physiological alterations of obstructive sleep apnea syndrome. Patients with obstructive sleep apnea syndrome and control populations have been studied using polysomnography and esophageal acid-base testing. They found that patients with obstructive sleep apnea syndrome were more likely to suffer from GERD than controls. In patients with obstructive sleep apnea syndrome, 53.4% of gastroesophageal reflux episodes were associated with apnea or hypopnea, and 46.8% of apneas were associated with acid reflux. Continuous positive airway pressure therapy reduced gastroesophageal reflux in both patients with and without obstructive sleep apnea syndrome, and anti-reflux therapy did not reduce the apnea-hypopnea index. Therefore, there is an association between obstructive sleep apnea syndrome and gastroesophageal reflux, but the relationship remains unclear. Another area of interest is the association of GERD with idiopathic pulmonary fibrosis. Foreign scholars have studied the results of barium gastroesophageal examinations in 48 patients with unexplained pulmonary fibrosis and confirmed a higher incidence of esophageal hiatal hernia and gastroesophageal reflux compared to controls. Gastric acid aspiration from a small number of tracheobronchial tubes repeatedly over a long period of time may lead to interstitial pulmonary fibrosis. Recently, dual-channel esophageal pH monitoring was used to evaluate 17 patients with biopsy-proven idiopathic pulmonary fibrosis and 8 patients with other interstitial lung disease. Sixteen of the 17 patients with idiopathic pulmonary fibrosis had abnormal distal and/or proximal esophageal acid contacts compared with 4 of 8 controls. Only 25% of the patients with idiopathic pulmonary fibrosis had the typical symptoms of GERD. The authors concluded that acid reflux may contribute to the pathogenesis of idiopathic pulmonary fibrosis. Although gastroesophageal reflux disease does have an association with idiopathic pulmonary fibrosis, there is no strong evidence for a pathophysiologic model of etiology. Anti-reflux treatment trials confirming improvement in idiopathic pulmonary fibrosis may be the best evidence for the pathologic role of GERD. Prevention of aspiration pneumonia in the elderly accounts for 1/3 of all pneumonia deaths, and prevention of aspiration pneumonia is an integral part of preventive care in the elderly: 1. Sleeping on the side is appropriate. Aspiration pneumonia in the elderly occurs mostly during sleep. The ability to swallow during sleep is reduced, the cough reflex is weakened, oral secretions flow backwards into the trachea, and pathogenic bacteria can migrate to the lower respiratory tract and cause infection. Therefore, elderly people should sleep in a slightly higher right-sided or semi-sided position to facilitate the flow of oral secretions and avoid the backflow of oral secretions into the trachea. Elderly people with gastroesophageal reflux disease especially need to maintain a side-lying position. 2. Pay attention to sputum discharge. The elderly are not easy to sputum, or even can not sputum, sputum easy to accidentally inhale the trachea and even the respiratory tract, constituting a common cause of aspiration pneumonia in the elderly. Long-term bedridden elderly every 2 hours turn, pat the back and massage the skin once, timely use of suction to aspirate the sputum out. 3, keep the oral cavity clean. Good oral care can significantly reduce the risk of aspiration pneumonia in the elderly. The elderly should pay attention to rinse their mouths or brush their teeth after 3 meals a day, and elderly patients who are hospitalized should do oral care 2 times a day, usually with 1% polyenpyrone gargle or swab the oral mucosa. 4, meals should not talk to prevent choking and coughing. If choking occurs, cough and tap on the back of the chest to cough out food particles. 5. Prevent triggering factors. Aspiration pneumonia is also associated with cold, overexertion and chronic rhinitis, sinusitis, chronic bronchitis and other triggering factors. The actual fact is that you will need to pay attention to the cold and warmth, and to combine work and rest to avoid triggering aspiration pneumonia.