Acid reflux is a common digestive discomfort symptom and is not a precursor of stomach cancer. Common discomfort symptoms of the digestive system include acid reflux, hidden pain in the abdomen, nausea and vomiting, etc. They are commonly seen in chronic gastritis, Helicobacter pylori infection or functional dyspepsia. Early gastric cancer may not have any symptoms, or the appearance of the above common discomfort symptoms of digestive system are not specific. Some gastric cancer patients may have the symptom of acid reflux in early stage, but relying on acid reflux alone cannot predict the occurrence of gastric cancer. When patients have black stool, unexplained weight loss and anemia, they need to be highly alert to whether they are suffering from gastric cancer or not, and the final diagnosis of gastric cancer needs to be made through gastroscopy and pathological examination, in which the condition of gastric mucous membrane can be observed, and biopsy of mucous membrane can be made to determine whether it is gastric cancer or not through pathological analysis. In daily life, paying attention to good dietary hygiene habits, quitting smoking and drinking, and timely treatment of gastric diseases can play a certain preventive role in the prevention of gastric cancer. For people over 40 years old or those with family history, regular gastroscopy can promptly detect the bad lesions in the stomach and treat them in time.