A gas in the chest rising and then coughing out is caused by indigestion, chronic gastritis, and gastric dysfunction. When food enters the stomach, it will be putrefied by digestive juices and then discharged into the duodenum. Once indigestion occurs, the digestion time of food will be prolonged, so it will stay in the stomach for a long time. The presence of food in the stomach for a long time will produce a lot of gas with the poor fermentation of digestive juices, and when too much gas is gathered, it will be discharged through the esophagus, and then the body will feel a gas rising in the chest, and then cough out the phenomenon. Chronic gastritis affects the peristaltic function of the stomach after a long period of illness, and therefore leads to belching, and when belching occurs, the gas goes up and is coughed out through the mouth, and the peristaltic function of the stomach is affected when emotionally stressed or depressed, leading to gastric dysfunction. The peristalsis of the stomach is relatively slow to empty the food and it ferments excessively in the stomach, resulting in a large amount of gas in the stomach and coughing it out through the esophagus.