Gastroesophageal reflux disease (GERD) is a condition in which gastric contents reflux into the esophagus causing uncomfortable symptoms and/or complications. The main symptoms are heartburn and reflux, and other rare or atypical associated symptoms include one or more of the following, such as epigastric pain, chest pain, belching, bloating, epigastric discomfort, pharyngeal foreign body sensation, sore throat, dysphagia, etc. In addition to extra-esophageal symptoms, there are also extra-esophageal symptoms, such as chronic cough, pharyngolaryngeal inflammation, asthma, otitis media, and respiratory sleep apnea. Due to work stress, frequent socializing, irregular meals, the incidence of gastroesophageal reflux disease is quietly rising, people’s awareness of such diseases is not high, only people take the initiative to consult the doctor, and because of the disease’s atypical symptoms, easy to be misdiagnosed as angina, respiratory diseases, such as pharyngitis, asthma, etc., a delay in the diagnosis and treatment, which in turn can lead to complications, such as esophagitis, hemorrhage, and serious life-threatening emergencies, such as asthma, laryngospasm, choking, etc., and long-term treatment can develop into a chronic cough, pharyngolaryngitis, asthma, otitis media, sleep apnea and so on. The long-term treatment of asthma can develop into precancerous lesions. Patients and medical personnel need to improve the correct understanding of the disease, so that patients will be less detour, early access to the correct diagnosis and treatment. The pathogenesis of GERD is the weakening of the defense mechanism and the decrease of esophageal acid clearance, which is mainly manifested by the decrease of the lower esophageal sphincter pressure (LESP) and the excessive transient lower esophageal sphincter relaxation (tLESR). The main damage factor of GERD is the reflux of excessive gastric contents (mainly gastric acid) into the esophagus, causing damage to the esophageal mucosa, and bile and digestive enzymes can also cause damage to the esophageal mucosa. The diagnosis of GERD is based on the following: 1. Diagnosis based on the symptoms of GERD: including typical heartburn and reflux symptoms, extra-esophageal symptoms, such as reflux-related cough, asthma; 2. Upper gastrointestinal endoscopy: helps to determine the presence of GERD as well as comorbidities and complications, such as hiatus hernia, inflammatory stenosis of the esophagus, esophageal cancer, etc.; 3. Diagnostic treatment: for the proposed diagnosis of patients or patients suspected of having extra-esophageal symptoms related to reflux, can be used for the diagnosis of patients with reflux. Diagnostic treatment: Diagnostic treatment can be used for patients with proposed diagnosis or suspected reflux-related extraesophageal symptoms. Proton pump inhibitor (PPI) diagnostic treatment is recommended to take a standard dose of PPI twice a day for 1 to 2 weeks; if the symptoms improve significantly after taking the drug, the diagnosis of acid-related GERD is supported; if the symptoms do not improve significantly, factors other than acid may be involved or do not support the diagnosis. the PPI test is not only helpful in diagnosing GERD, but also initiates the treatment; 4, the evidence of GERD Examination: (1) X-ray and radionuclide examination; (2) 24h esophageal pH monitoring: the significance of 24h esophageal pH monitoring is to confirm the presence or absence of reflux. 24h esophageal pH monitoring can show in detail the acid reflux, the pattern of diurnal acid reflux, the relationship between acid reflux and the symptoms as well as the patient’s response to the treatment, which enables the treatment to be individualized. Its positive rate for GERD is >75%. 5, esophageal manometry; 6, esophageal bile reflux measurement; 7, other: the study of the ultrastructure of the esophageal mucosa can understand the pathophysiological basis of the existence of reflux; wireless esophageal pH measurement can provide a longer period of acid reflux detection; the application of intraluminal impedance technology can monitor all reflux events, to clarify the nature of the reflux material (gas, liquid, or gas-liquid mixtures), and with the combined application of the monitoring of esophageal pH can clarify the reflux material is acidic or non-acidic. whether the reflux is acidic or nonacidic and the relationship between reflux and reflux symptoms.