The Carbon 14 Breath Test can be done twice a day, but the sensitivity of the Carbon 14 Breath Test is high enough that it is usually not necessary to perform the test twice a day. The Carbon 14 Breath Test is a test to detect the presence of H. pylori infection in the stomach. During the test, the patient is asked to take one carbon-14 labeled urea by mouth, sit still for half an hour, and then blow into a collection bag to collect the gas and test for the presence of carbon-14 labeled carbon dioxide. The carbon 14 breath test can be performed twice in one day, but the sensitivity of this test is high, and a result greater than 100 dpm is considered positive, so it is usually not necessary to perform the test twice in one day. Carbon 14 is a radioactive marker, although the radioactivity is very small, but still will have a certain amount of radiation to the organism, especially for pregnant women, children and other groups of people who are more sensitive to radioactive damage, it is not recommended to do carbon 14 test. If the patient’s carbon 14 breath test result is positive, it is recommended to seek prompt medical attention and actively receive treatment to avoid delaying the condition.