H. pylori infection, which is now more common in China, with a high infection rate of 50%-60%, is a major causative factor for indigestion, gastritis, peptic ulcer, and gastric cancer. Some patients may have no symptoms after infection, while others may experience epigastric pain, bloating, nausea, vomiting, belching, acid reflux and heartburn, as well as bad breath and bad taste in the mouth after H. pylori infection. If a patient exhibits these symptoms, it is recommended to go for a carbon 13 or carbon 14 breath test to clarify the presence or absence of H. pylori infection. Also for patients older than 40 years old, or patients with a family history of tumors, such as parents with stomach tumors, it is recommended to also improve gastroscopy to clarify the presence of peptic ulcers or early gastric cancer.