H. pylori carbon 13 breath test is a “qualitative” test, the normal value of ≤ 4dpm, the result of 18dpm only indicates the existence of H. pylori infection, but can not determine the severity of the lesion. The carbon 13 labeled urea taken orally by H. pylori infected people can be decomposed by H. pylori in the stomach, and carbon 13 can be detected in the exhaled carbon dioxide; normal people do not have H. pylori in the stomach, and the carbon 13 labeled urea taken orally will not be decomposed, and no carbon 13 can be detected in the exhaled carbon dioxide; therefore, the H. pylori carbon 13 breath test is the test for determining whether H. pylori infection exists. Determining the severity of the condition relies heavily on the presence of gastric symptoms and the presence of H. pylori-associated diseases such as atrophic gastritis, peptic ulcer, and gastric cancer. H. pylori infection is highly associated with a variety of gastric diseases, and it is recommended that infected individuals go to a regular hospital for treatment and rechecking to avoid persistent infections that can lead to serious lesions.