If you have always been well, but gradually find discomfort or pain in the stomach (equivalent to upper abdomen), which cannot be relieved by taking pain and acid-relieving drugs, and continue to have poor digestion, you should be alert to the occurrence of gastric cancer. Alert groups: those who prefer pickled food in their diet, those who have atrophic gastritis, pernicious anemia, family history of gastric or colorectal cancer, those who have blood type A, those who are more than 10 years after gastrectomy, those who have smoking habit, and those who are infected with H. pylori in the stomach. Measures for early detection: Regular gastroscopy, once every one to two years. Patients over 50 years of age with the following suspected symptoms: upper abdominal pain, bloating, loss of appetite, anemia, vomiting blood, black stools, or unexplained weight loss should immediately consult a gastroenterologist. Preventive measures: avoid irritating food and over-eating, moderate alcohol consumption, prevent overeating; eat less pickled, smoked, baked and fried foods; eat fresh vegetables and fruits containing vitamin C regularly; actively treat gastric ulcer and atrophic gastritis.