In the early stage of gastric cancer, most patients have no obvious symptoms, and a few of them have nausea, vomiting, epigastric discomfort, dyspepsia, belching and other five early symptoms, which are non-specific. When specific symptoms appear, it has already reached middle or late stage. Gastric cancer is a malignant tumor originated from gastric epithelium and is one of the most common malignant tumors in China. It can develop at any age, and most of them occur in middle and old age. The causes of gastric cancer include Helicobacter pylori infection, environmental factors and genetic factors. Early stage of gastric cancer is mostly asymptomatic, only epigastric discomfort and indigestion, etc. With the progress of the disease, there may be epigastric pain, weight loss, loss of appetite, vomiting and black stools in case of pyloric obstruction. Surgery is the main method to treat gastric cancer. Gastric cancer can be prevented by preventing Helicobacter pylori infection, dietary hygiene, abstaining from smoking and limiting alcohol, actively treating atrophic gastritis and gastric ulcer. If you have any discomfort such as epigastric discomfort, nausea, belching, etc., please go to regular hospitals to be examined and treated by professional doctors in time.