Early stage of gastric cancer often has only some non-specific digestive tract symptoms or no symptoms at all. Therefore, it is very difficult to diagnose early gastric cancer based on clinical symptoms alone, so with a view to early detection, going to specialist medical examination is undoubtedly the best method. The earliest symptom of progressive gastric cancer is often upper abdominal pain, which is often accompanied by poor appetite, anorexia and weight loss. The abdominal pain can be acute or slow, starting with epigastric fullness and discomfort, which is worse after meals, followed by vague discomfort and occasional rhythmic ulcer-like pain, but this pain cannot be relieved by eating or taking acid suppressants. Patients often have a sense of early satiety and weakness. Early satiety is a feeling of fullness and discomfort as soon as the patient eats, even though he or she is hungry. Early satiety or vomiting is a sign of gastric lining involvement, which is especially prominent in leathery stomach or partial obstruction. Therefore, if the symptoms of epigastric pain appear at the age of 40 or above, it should be paid enough attention and active examination should be conducted. In early stage of gastric cancer, there is no obvious sign, but in the progressive stage, a mass can be found in the upper abdomen with pressure pain. The mass is mostly located in the upper abdomen to the right of the gastric sinus. If the tumor metastasizes to the liver, it may cause liver enlargement and jaundice, or even ascites. If there is metastasis to the peritoneum, ascites may also appear, and the mobile turbid sound is positive. The spleen may be enlarged when the portal vein or splenic vein is invaded. Virchow’s lymph node (left supraclavicular) can be found in the presence of distant lymph node metastases and is hard and inactive. A plate-like mass can be found in the rectal bladder recess on anal examination. Gastric cancer with complications or metastasis may present some special symptoms. Nausea and vomiting may occur when pyloric obstruction is involved, and vomiting of blood or black feces may occur when ulcerated gastric cancer bleeds, followed by anemia. Metastasis of gastric cancer to liver may cause pain in the right upper abdomen, jaundice and fever; metastasis to lung may cause cough, eructation and hemoptysis, and involvement of pleura may produce pleural effusion and dyspnea; when tumor invades the pancreas, radiating pain in the back may occur. Patients with progressive gastric cancer may have low gastric acid and diarrhea, which is mostly thin stool, 2-3 times a day. Some gastric cancers may develop paraneoplastic syndrome, including recurrent superficial thrombophlebitis and hyperpigmentation; acanthosis nigricans, hyperpigmentation in skin folds, especially in both axillae; dermatomyositis, membranous nephropathy, neuromuscular lesions involving sensory and motor pathways, etc.