The C14, or carbon 14 breath test, is a test to detect Helicobacter pylori. This test requires fasting, that is, do not eat, do not drink water. This is because the presence of food in the stomach will prevent the carbon 14 urea capsule from coming into contact with the gastric mucosa, thus affecting the accuracy of the test result and resulting in a false negative. If the test result shows positive, it suggests that Helicobacter pylori infection, which needs to be timely consultation and treatment. Mainly, quadruple therapy is adopted, i.e. one proton pump inhibitor, two antibiotics and one bismuth agent, such as omeprazole, amoxicillin, clarithromycin and bismuth potassium citrate. In addition to this, the accuracy of the test results may also be affected by taking medications such as proton pump inhibitors within 2 weeks prior to the test and antibiotics as well as bismuth within 1 month prior to the test, resulting in false negatives. Carbon 14 breath test has the advantages of being painless, non-invasive, rapid and accurate. If the test result is positive, you need to follow the doctor’s advice in time.