The H. pylori breath test, which is mainly monitored under the premise of fasting, is usually fasted for more than 6-8 hours. Choose the morning examination, take the capsule orally, observe for about 15 minutes, then blow the card, through the exhaled gas, the amount of carbon 13 or carbon 14 can be detected on the card to indirectly reflect the active level of H. pylori in the stomach. Generally in 0-110 is the normal range, if it exceeds 700, anti-H. pylori medication is needed; below 200, it is not necessary to give symptomatic treatment. About 1 week before the H. pylori monitoring, it is not possible to take antibiotics, while doing exhalation, as smooth as possible, is like blowing up a balloon, try not to force too hard, otherwise it is easy to lead to hypoxia.