The symptoms of acid reflux are mainly caused by stomach diseases, such as superficial gastritis, gastric ulcer and gastric sinus cancer. This is because pathological changes in the stomach can cause destructive damage to local normal tissues. When the patient drinks water, the volume of gastric acid in the stomach increases, and the contact reaction between the gastric acid and the patient induces a contractile spasm of the smooth muscle. The acid in the stomach will reflux to the esophagus and chest cavity due to the increased internal pressure, and cause stimulation to the local mucosal tissues, resulting in symptoms such as gastric distension, acid reflux and vomiting, and sternal pain. However, it does not exclude the possibility of other diseases such as duodenal bulb ulcers, pancreatic cancer, bile duct stones, etc. Because of the proximity of the above organs and tissues to the stomach, local organic lesions may cause pressure and irritation to the outer mucosa of the stomach, resulting in frequent symptoms of acid reflux.