General anesthesia generally refers to general anesthesia, and it is necessary to abstain from food and water before anesthesia to avoid food reflux during anesthesia and blocking the airway. It is recommended that patients should avoid eating for 6~8 hours before general anesthesia surgery, in addition, patients need to prohibit drinking water for 2~4 hours before general anesthesia surgery. Because patients may vomit and have reflux of stomach contents after general anesthesia, if patients eat before general anesthesia surgery, it may lead to aspiration of vomit and enter into the trachea. Patients may develop aspiration pneumonia, airway blockage, and in serious cases, it may even cause suffocation or death. It is recommended that patients need to fast 6 to 8 hours before general anesthesia surgery. In this way, there is usually no residual food in the stomach during anesthesia, so that gastric reflux does not lead to blockage of the trachea or result in aspiration pneumonia.