Diaphragmatic Training on GERD

Include Criteria: * Age between 20 and 80 years.2. A confirmed diagnosis of gastroesophageal reflux disease (GERD), defined by at least one of the following criteria * Endoscopic examination within the past 3 months demonstrating Los Angeles (LA) grade A reflux esophagitis with regular use of acid-suppressive medication (e.g., proton pump inhibitors) for more than 2 months. * 24-hour esophageal pH monitoring showing acid exposure time (AET) \> 6%. * Endoscopic examination within the past 3 months demonstrating LA grade B or higher reflux esophagitis. * Willingness and ability to participate in the intervention program, including adherence to training protocols, scheduled follow-up visits, and completion of all required assessments during the study period. Exclusion Criteria * Pregnant or breastfeeding women. * History of anti-reflux surgery or other upper gastrointestinal surgical procedures related to GERD. * Presence of significant cardiopulmonary disease or chronic respiratory disease that may compromise the safety or feasibility of performing breathing training. * Inability to comply with the study protocol, including participation in training procedures and scheduled follow-up visits, due to conditions such as cognitive impairment, physical limitations, or inability to attend regular visits.