H. pylori is a major concern, gastroenterology visits with upper abdominal discomfort, or in many units physical exams to test for H. pylori, the common method is the carbon 13 or carbon 14 urea breath test, they are non-invasive means of testing. Why use this tool? H. pylori has urease activity, can break down urea into carbon dioxide and ammonia, that use this principle, with the isotope carbon 13 or carbon 14 to mark the carbon atoms in urea, through the human body after oral intake, H. pylori metabolism into carbon dioxide exhaled out of the body, through specific instruments to monitor, through the changes before and after taking the drug to determine whether the human body has H. pylori infection. The commonly used carbon 13 or carbon 14 are more accurate, the only difference is that carbon 14 has a longer half-life and may cause some pollution to the atmosphere. So for pregnant women or children, it is not recommended to use carbon 14 to do the test, such people can use carbon 13, because carbon 13 is a stable isotope, there will be no harm to the human body and the environment, so as long as the conditions of the unit advocate the use of carbon 13 breath test.