Gastritis, improper diet, and reflux esophagitis can easily lead to acid flow. The phenomenon of acidity in the mouth is mainly caused by stomach diseases, more common are gastritis, often eat irritating food, long-term use of erythromycin, prednisone will lead to damage to the gastric mucosa, thus forming inflammation and ulcers in the stomach. When the stomach is empty and more food is consumed there will be increased secretion of gastric acid, which causes acid vomiting. Due to work, many people wake up in the morning and rush to work, and often do not eat breakfast will lead to more space in the stomach, which will lead to increased secretion of stomach acid will flow from the mouth. Stomach acid reflux is just a clinical symptom, considered to be caused by reflux esophagitis, most patients tend to appear about an hour after meals, because the intake of more food will cause pressure on the stomach wall, easy to appear acid reflux, heartburn.