A negative RAC indicates that no regular submucosal collecting veins were found during gastroscopy. RAC is the acronym for regular submucosal collecting veins, which are observed in the collecting veins of the body and fundus of the stomach while the patient is undergoing gastroscopy. Normally, the collecting veins in the stomach are regular in shape, but in the case of H. pylori infection, irregular deformation occurs leading to the disappearance of the RAC, so the RAC test is one of the specific indicators for confirming the diagnosis of H. pylori infection. After being infected with H. pylori, the incidence of gastritis, gastric ulcer and other gastric diseases will increase, so it is recommended that patients seek medical treatment in time to avoid delays.