Blowing for H. pylori is mostly done by carbon 13 or carbon 14 breath test. The test requires the oral administration of carbon 13 or carbon 14 urease capsules and the application of a specific instrument to detect excess carbon dioxide in the exhaled gas and to check for H. pylori infection. The test is suitable for those who are suspected of having H. pylori infection. H. pylori is associated with acute and chronic gastritis, gastric ulcer, duodenal ulcer, gastric sinusitis, mucosa-associated lymphoid tissue lymphoma and other diseases, and the breath test can be used for rapid preliminary differential diagnosis, as well as for preventive examination of those with a family history of gastric cancer and for evaluation of efficacy and diagnosis of recurrence after H. pylori eradication treatment. Among them, the carbon 13 test is radiation-free and more suitable for children and pregnant women, while the carbon 14 test test has some radiation and is generally not recommended for pregnant or breastfeeding women. Usually, a positive test result indicates the presence of H. pylori infection, which can be eradicated by applying quadruple therapy under the guidance of a doctor. In addition, drugs such as bismuth, proton pump inhibitors, and antibiotics need to be avoided before the test, and fasting is required on the day of the test. The capsule needs to be taken orally intact with warm water during the test, and should not be bitten into, so as not to affect the accuracy of the test results. If you have acute bleeding in the upper gastrointestinal tract, the test should be performed a week after the gastrointestinal bleeding has stopped. Gastrectomy surgery may cause rapid emptying of the isotope from the stomach, which will affect the detection of H. pylori.