What is gastroesophageal reflux disease? Simply put, it is the reflux of gastroduodenal contents into the esophagus causing symptoms such as heartburn, and can cause reflux esophagitis, as well as damage to the adjacent tissues of the esophagus such as the throat and airway. Reflux esophagitis can be detected by endoscopy, but some patients with GERD do not show signs of esophagitis on endoscopy, and this type of GERD is also called endoscopically negative GERD or non-erosive reflux disease (NERD). What are the main symptoms of GERD? I. Esophageal symptoms 1. Typical symptoms: heartburn and reflux! Remember these four words! What is reflux? Reflux is the sensation of stomach contents rushing into the throat or mouth without nausea or exertion, and is called acid reflux when it contains an acid taste or is just sour water. What is heartburn? Heartburn is a burning sensation behind the sternum or under the glabella (often referred to as the fossa of the heart), often extending upward from the lower end of the sternum. The above two symptoms are often realized one hour after a meal and can be aggravated in a flat position, bending over or when intra-abdominal pressure increases (picking up heavy objects, violent coughing, etc.). 2. Atypical symptoms: These are esophageal symptoms other than heartburn and reflux symptoms, including chest pain and difficulty in swallowing. Extra-esophageal symptoms are caused by reflux that irritates or damages tissues or organs outside the esophagus, such as chronic pharyngitis, chronic cough and asthma, and foreign body sensation in the pharynx. What is foreign body sensation in the pharynx? Patients are often seen with a foreign body sensation in the pharynx. Simply put, a feeling of discomfort in the pharynx, a feeling of cotton ball or blockage, but no real difficulty in swallowing, and some patients even feel that there is phlegm in the pharynx but cannot cough it up. A preliminary diagnosis of GERD can be made by the above symptoms. Further diagnosis can be made by diagnostic treatment with a proton pump inhibitor (PPI test) under the guidance of a medical professional. What is (PPI test)? Acid reflux plays an important role in GERD. Patients with typical symptoms of heartburn, reflux with a diagnosis of GERD or extraesophageal symptoms associated with suspected GERD who have negative gastroscopy may be treated with a diagnostic proton pump inhibitor (e.g. omeprazole, esomeprazole, rabeprazole, etc.) (PPI test). PPI test is proven to be easy and effective, and patients are usually given standard doses of PPI bid, such as esomeprazole 20mg; rabeprazole 10mg, orally before breakfast and 30 minutes before dinner, respectively, for 1~2 weeks to observe whether the heartburn and reflux symptoms are reduced, and if the symptoms are reduced by 50% or more, a positive PPI test can be judged, and the diagnosis of non-erosive gastroesophageal reflux disease ( NERD).