The carbon 14 urea breath test or carbon 13 urea breath test is a test to detect the presence of H. pylori infection. If the test result is positive, then the patient is diagnosed with H. pylori infection. It is recommended that the patient should first complete a gastroscopy to rule out the presence of organic diseases of the upper gastrointestinal tract, such as chronic gastritis, peptic ulcer, gastric cancer or gastric lymphoma. If the patient has malignant diseases, such as gastric cancer or gastric lymphoma, then it is recommended that the patient should go to the general surgery department or hematology department for further consultation, surgery, chemotherapy and other treatments. If the patient’s gastroscopy is benign or negative, it is recommended that the patient should be treated with regular anti-Helicobacter pylori quadruple therapy for 10-4 days, and then stop taking the medication for four weeks and repeat the carbon 14 breath test.