A C14 breath test <100 is in the normal range, indicating no Helicobacter pylori infection. C14 breath test is used to determine whether there is H. pylori infection by detecting the presence of CO2 labeled by C14 after taking carbon 14 labeled urea. Infection with H. pylori can easily induce gastritis, gastric ulcer, gastric erosion and other diseases, and can also lead to an increased incidence of gastric cancer. Therefore, H. pylori infection should be treated with H. pylori eradication therapy, usually with triple and quadruple therapy. If you have gastrointestinal discomfort symptoms, even if the C14 test result is normal, you should go to the hospital in time to clarify the cause of the disease and standardize the treatment, so as to avoid delaying the disease and worsening the condition.