Breath test is the preferred method to detect H. pylori infection, mainly C13 and C14 urea breath test, as follows: a. Breath test to detect H. pylori is mainly C13 and C14 urea breath test urea can generate ammonia and carbon dioxide under the action of urease, in the breath test patients first take a marked C13 or C14 urea, if the patient’s body has H. pylori If the patient has H. pylori in his body, it can be decomposed into ammonia and carbon dioxide, and the isotopically labeled carbon dioxide will be excreted through the lungs, so it can be detected by breath, and the more isotopically labeled carbon dioxide, the more serious the situation of H. pylori infection. Second, the breath test is non-invasive and painless, reducing the pain of patients, and high sensitivity, high accuracy rate of detection, will not cause cross-infection, so the detection of H. pylori preferred breath test method.