Many patients with gastric problems go to the hospital and are told that their stomach is infected with a bacteria called H. pylori, and they hear that they can get stomach cancer without timely treatment, so they also carry a heavy psychological burden. So how exactly does H. pylori get infected and how harmful is it to the human body? The following I will talk about those things about H. pylori. H. pylori is a bacteria growing on the surface of the gastric mucosa, first discovered by Australian scholars in 1982 and won the Nobel Prize in medicine for this. The infection rate of H. pylori in the global population is more than 50%, and the infection rate of different regions and ethnic groups in China is 30%-80%. It is mainly transmitted through the oral-oral or fecal-oral route. This means that infection is possible with shared meals or contaminated hands, so good hygienic habits can help prevent H. pylori infection, but in today’s reality it is really impossible to prevent it. What diseases does H. pylori cause? H. pylori infection is difficult for the body to clear on its own, and if left untreated often results in lifelong infection. (1) Almost all H. pylori infections eventually develop into gastritis, which is the most common cause of chronic gastritis, but most patients can be asymptomatic, and some can have indigestion symptoms such as bloating, early satiety, and burping; (2) 15-20% of patients develop gastric or duodenal ulcers; (3) Less than 1% of infected patients develop gastric cancer, but it is important to note that gastric cancer is a multi-step process. (3) less than 1% of infected patients will develop gastric cancer, but it should be noted that the occurrence of gastric cancer is a multi-step process, which is the result of a combination of H. pylori infection, patient’s own factors and environmental factors, rather than the fault of H. pylori alone, so perhaps it is more accurate to say that H. pylori can increase the risk of gastric cancer; (4) H. pylori is closely associated with the occurrence of a type of gastric lymphoma. How do I know I have H. pylori infection? The main methods for diagnosing H. pylori infection include invasive methods that rely on gastroscopic biopsy and non-invasive methods that do not rely on gastroscopy. The first is to remove a piece of gastric mucosal tissue the size of a grain of rice under the gastroscope at the same time as the gastroscopy for laboratory testing, usually the rapid urease test method commonly used in clinical practice can produce results in a few minutes. “The second method is designed to simply check for H. pylori, and the most commonly used and accurate clinical test is the carbon 13 or carbon 14 breath test, which is simple, convenient and fast. Patients take carbon 13 or carbon 14 punch (capsule) orally during the test after 2 hours on an empty stomach or after a meal, and after half an hour on an empty stomach, patients can breathe into the test instrument. Regardless of the test method patients are advised not to take omeprazole-type acid suppressants and antibiotics for 2-4 weeks before the test, otherwise the test results will be affected.