Gastritis is not contagious and is not infectious in any way. The so-called gastritis is mainly caused by the formation of congestion, edema, erosion, and even mild ulcers in the mucosal layer of the stomach due to dietary inattention. Most of the gastritis is related to their own diet, such as eating some stimulating and spicy food, or frequent drinking, smoking, irregular diet resulting in more stress, causing long-term insomnia, worry, anxiety, etc., causing gastritis to occur. The common clinical gastritis with H. pylori infection, itself H. pylori is a certain degree of contagious. The gastritis is the result and not the cause of H. pylori, so gastritis is not contagious. The so-called contagiousness refers to the contagiousness caused by the infection of H. pylori, which is transmitted by the fecal-oral route. Therefore, for positive carbon 13 and carbon 14 breath tests (+) and DPM greater than 500, anti-H. pylori medication needs to be given to prevent secondary H. pylori infection caused by the fecal-oral route of transmission.