The reference value for the carbon 13 breath test is less than or equal to 4. If the test value is greater than this value, the test result is positive. The initial diagnosis of H. pylori infection is based on the ability of H. pylori to break down urea, and the isotope labeling method is used to detect the uniformity of the exhaled carbon dioxide content of the subject to make a definitive diagnosis of the condition. The subject will take the test meal orally, perform a zero-hour breath collection on the breath test tube, then will take the urea agent containing C13 again, wait for 30 minutes, and then use another breath test tube for breath collection. The two breath test tubes are then placed in the breathalyzer for specific analysis and the difference between the two measurements is observed. It is important to note that the carbon 13 test requires the subject to remain fasted or eat for at least two hours before this test can be performed. Patients taking antibiotics, proton pump inhibitors, or other types of medications should inform their primary care physician in advance to avoid affecting the accuracy of the test results.