A carbon 13 test of 90dpm/mmol indicates the presence of H. pylori infection, which is generally not serious if there is no discomfort or if it is combined with mild gastritis, but more serious if it is combined with gastric cancer and other diseases. Carbon 13 breath test is mainly used to detect whether there is H. pylori infection, 0 to 4 is the normal value range of the test, if significantly more than the range suggests that there is H. pylori infection, so the test value of 90dpm/mmol is generally considered to be the existence of the bacteria infection. The severity of H. pylori infection has nothing to do with the number of test values, but is mainly related to the severity of the disease caused by H. pylori. If there is no obvious stomach discomfort or only mild gastritis or gastric ulcer, it is not a serious condition; however, if it causes gastric cancer and other diseases, then it suggests that the condition is serious. Positive patients should go to the hospital for timely treatment and exclude other possible diseases, as prescribed by the doctor.