In current medical clinics, C13 and C14 breath tests are the most commonly used tests for detecting H. pylori infection, and the reagents used are different and there are different testing standards. The normal range of C14 breath test is 0~150, and a test value between 150~200 is a suspicious infection, and a test value greater than 200 indicates a positive test result. The above two breath tests have an accuracy rate of 97% or more. In addition, it should be noted that the subject should avoid eating any food 3 hours before the test, and should not take antibiotics, H2 receptor antagonists, bismuth and other types of drugs for the first 2 weeks to avoid affecting the accuracy of the test results.