Causes Environmental and Dietary Factors The obvious difference in the incidence rate in different countries and regions indicates that it is related to environmental factors, the most important of which is dietary factors. Excessive intake of salt, salted foods with high salt content, smoked fish, and foods with nitrosamines are some of the factors associated with gastric cancer, as well as moldy foods that contain high levels of mycotoxins, and rice processed with talcum powder on the outside. In addition, there are also studies showing that stomach cancer is related to the imbalance of nutrients. Frequent consumption of moldy food, pickles. Pickled and smoked foods, as well as excessive salt consumption, can increase the risk. Eat plenty of fresh fruits and vegetables. Using a refrigerator and storing food properly can reduce the incidence of stomach cancer. Helicobacter pylori Infection Helicobacter pylori disease is a spiral-shaped, slightly anaerobic bacterium that requires very demanding growth conditions.It was first successfully isolated in 1983 from gastric mucosal biopsies of patients with chronic active gastritis, and it is the only species of microorganism known to be able to survive in the human stomach. H. pylori disease includes gastritis, peptic ulcer, and lymphoproliferative gastric lymphoma caused by H. pylori infection. The poor prognosis for H. pylori disease is gastric cancer. Gastric cancer may be the result of long-term H. pylori infection in conjunction with other factors*** in which H. pylori may play a predisposing role. Genetic factors The incidence of stomach cancer is higher in certain families. The incidence of stomach cancer in relatives of stomach cancer patients is four times higher than that in normal people. Some data show that stomach cancer occurs more often in people with blood type A than in people with blood type O. Immunity factors The incidence rate of stomach cancer is higher in people with low immunity function. Symptoms of various stages of gastric cancer 1. More than 70% of early gastric cancers have no obvious symptoms, but with the development of the disease, non-specific symptoms similar to gastritis or gastric ulcer may appear gradually, including fullness, discomfort or hidden pain in the upper abdomen, acidity, belching, nausea, occasional vomiting, loss of appetite, dyspepsia, positive fecal occult blood or black stools, unexplained fatigue, lethargy, or progressive anemia, etc. 2. 2. Symptoms of progressive gastric cancer (i.e. middle and late gastric cancer) include pain in stomach area, which is often biting and not obviously related to eating, or similar to peptic ulcer pain, which can be relieved after eating. There are feeling of fullness and heaviness in the upper abdomen, anorexia, abdominal pain, nausea, vomiting, diarrhea, emaciation, anemia, edema, fever and so on. Cancer of cardia mainly manifests as discomfort, pain or retrosternal pain under the raphe, accompanied by obstruction of eating or difficulty in swallowing; cancer of gastric fundus and subcardia often has no obvious symptoms, and only attracts attention when the tumor is huge and necrosis and ulceration cause upper gastrointestinal tract bleeding, or when the tumor infiltration extends to cardia and causes difficulty in swallowing; cancer of gastric body is more common in the ballooning type, and pain and discomfort appear later; cancer of gastric sinus is most common in ulcerative type, and most common in ulcerative type, and most common in gastric sinus. When the tumor extends to the pyloric orifice, it can cause nausea, vomiting and other symptoms of pyloric obstruction. When the tumor extends to the pyloric valve, it can cause nausea, vomiting and other symptoms of pyloric obstruction. Metastatic spread of cancer can cause ascites, liver enlargement, jaundice, and metastasis to lungs, brain, heart, prostate, ovary, bone marrow and other corresponding symptoms. High risk factors of stomach cancer The main risk factors of stomach cancer include: a. Long-term consumption of high salt, smoked products and salt-pickled food has a promoting effect on the occurrence and development of stomach cancer. b. Poor dietary habits, such as eating high salt, smoked products and salt-pickled food, has a promoting effect on the occurrence and development of stomach cancer. Those who have bad dietary habits, such as eating fast, loving hot and scalded food and not eating three meals a day on time. b. Those who have atrophic gastritis, gastric ulcer, gastric polyp, intestinal metaplasia, pernicious anemia and residual stomach after most of the gastric resection are at risk of cancer. c. People with family history of gastric cancer. d. Those who are over 40 years old and have long time of untreated gastric disease; those with blood type A combined with the above factors are more likely to suffer from gastric cancer. Early warning signals of stomach cancer a. Upper abdominal fullness, discomfort, hidden pain or change of pain pattern. b. Acid, pain in the stomach, pain in the stomach, pain in the stomach, pain in the stomach, pain in the stomach, pain in the stomach. b. Sourness, belching, loss of appetite, nausea, heartburn, diarrhea and black stool. c. Unexplained weight loss and significant emaciation. d. Above 50 years of age with no past history of stomach pain or gastric problems and short-term onset of gastric symptoms. Those who have recovered well from a major gastrectomy for a benign disease of the stomach many years ago and have recently experienced indigestion, epigastric pain, nausea, vomiting, black stools, and a marked decline in health. Although these symptoms do not mean that they have stomach cancer, when the above symptoms continue to be unrelieved, they should go to the hospital and ask the doctor for detailed examination. Self-discovery of stomach cancer Most of the early stomach cancers do not have obvious symptoms, but only epigastric discomfort, bloating and loss of appetite after eating. These symptoms are often similar to common indigestion, gastritis or gastric ulcer, but some early patients with hidden pain may also have bleeding and black stool. If the recurrence of epigastric pain and discomfort, postprandial bloating, loss of appetite, according to the common gastric treatment is ineffective and progressive aggravation, wasting, anemia and other symptoms. In addition, if there is a history of ulcer disease and gastritis, but the symptoms are recurring, ineffective in treatment, worsening, sometimes vomiting of food or tendency to vomit blood and black stool (including positive fecal occult blood test), one should think of the possibility of gastric cancer. Generally speaking, if the tumor grows at the entrance of stomach (cardia), there is difficulty in swallowing, pain behind the sternum, food friction and stagnation when swallowing food; if the tumor grows at the exit of stomach (pylorus), it can cause epigastric distension and discomfort after meals, vomiting and obstruction symptoms.