Generally, the normal range of H. pylori is 0~4dpm in case of C13 breath test and 0~100dpm in case of C14 breath test. For the C13 breath test, the patient needs to take a capsule orally after 3 hours of fasting, and then blow out the gas after 15 minutes, and then the gas is detected.The normal range of the C13 test breath test is 0~4dpm.The result of the test is positive beyond 4dpm, indicating that it is infected with Helicobacter pylori. C14 breath test in the test patients need to fasting for more than 12 hours, then oral C14 capsule, 15 minutes after blowing to the gas, and then gas detection.C14 breath test normal range is generally 0 ~ 100dpm, if the test result is more than 100dpm, it indicates that the infection of Helicobacter pylori. It is important to note that infection with H. pylori should be treated promptly to avoid delays.