The breath test is relatively accurate for monitoring H. pylori, and statistics show that its sensitivity and specificity are over 95%. Therefore, the breath test is the preferred test by clinicians, especially gastroenterologists. The H. pylori breath test is chosen because H. pylori has its own specificity. H. pylori has strong urease activity, which can break down urea into carbon dioxide and ammonia, and carbon dioxide can be detected by exhaling out of the body. The carbon atoms inside the urea are labeled with the isotope carbon 13 or carbon 14, which are collected with specific instruments after exhalation, and the before and after changes are detected to determine the presence of H. pylori. In clinical practice, carbon 13 is advocated for H. pylori breath testing because it has a short half-life, can be used by pregnant women and children, and is not polluting to the atmosphere, so it is used in most places where it is available. carbon 14 is also used clinically, but it has a relatively long half-life, so children, pregnant women, and lactating women should not choose carbon 14 breath testing. In addition, the following precautions should be taken when doing the breath test: 1) fasting; 2) do not move around excessively during the test to avoid excessive exhalation of carbon dioxide gas, which may affect the accuracy of the test results; 3) do not eat before the test, as the test may be affected when eating; 4) give a clear account of the recent use of drugs to the clinical doctor during the test to determine whether it is suitable for the breath test In order to avoid false positives or false negatives that could lead to financial losses and influence the doctor’s judgment. In conclusion, the breath test for H. pylori is a widely used test in clinical practice, with good accuracy, specificity and sensitivity.