Pathophysiological mechanisms of asthma due to reflux esophagitis: Two mechanisms are thought to be involved: 1. It is thought that respiratory symptoms are caused by misaspiration of gastric contents. 2. It is believed that acidification of the low esophagus stimulates the vagus nerve, which makes the bronchi constrict and causes coughing and wheezing symptoms. How to diagnose asthma due to GERD: The diagnosis can be made with reflux symptoms and secondary respiratory symptoms. However, there are many patients with only coughing and wheezing symptoms. In these patients, acid reflux is insidious and can only be detected by performing relevant tests. For asthmatic patients who have failed to respond to medical respiratory medication, relevant tests for GERD should be performed. If GERD is diagnosed or a hernia is present, surgical consultation should be requested and surgical treatment should be performed, and this concept should be established. Related tests include: 24-hour PH monitoring, which is the gold standard for diagnosing GERD; endoscopy, which can detect esophagitis or Barrett’s esophagus; and esophageal manometry, which can evaluate the pressure of the esophageal sphincter and the motility of the esophagus. Technetium sulfur gel scintigraphy and isotope imaging methods have poor sensitivity and are less commonly used.