If the DOB of carbon 13 breath test is ≥4dpm, H. pylori infection is considered to be present, and if the DOB is <4dpm, H. pylori infection can generally be excluded. Clinically, the normal reference range of DOB value of carbon 13 breath test is 0~4dpm, and H. pylori infection is considered to exist if DOB≥4dpm. However, it should be noted that taking antibiotics, bismuth preparations or proton pump inhibitors within 1 month before the test may cause false negatives, resulting in missed diagnosis. If infected with H. pylori, a quadruple drug antimicrobial therapy, i.e., a combination of omeprazole, bismuth potassium citrate, metronidazole, and clarithromycin, is required for treatment, and the patient needs to be reviewed regularly during the treatment period. If the carbon 13 breath test result is abnormal, it is recommended that the patient should consult a doctor in time, combining with the symptoms and further examination for diagnosis, and actively carry out treatment.