Malnutrition edema is mostly related to hypoproteinemia and vitamin B1 deficiency, and the most common causes of malnutrition edema can be understood as two types of insufficient intake and too much consumption, as follows: 1, the daily diet nutritional structure ratio is not coordinated, not enough nutrition intake, causing malnutrition; 2, the impact of disease, common gastrointestinal and digestive tract diseases, such as gastric cancer, most of the post-gastrectomy, or acute and chronic gastritis especially chronic gastritis is common, or pancreatitis, can cause malnutrition; 3, tuberculosis, liver cirrhosis, nephritis and other diseases appear nausea, vomiting, resulting in digestive malabsorption syndrome, can also appear malnutrition intake; 4, long-term massive consumption, long-term fever, such as cancer, nephritis patients, there is a large amount of protein urine loss more, or burns, burns, skin surface ulcer surface exudation, So that protein loss caused by malnutrition; 5, also seen in diabetic patients with excessive fat and protein decomposition, decomposition into ketone bodies and glucose from the urine, resulting in excessive protein decomposition. Therefore, the above-mentioned gastrointestinal and digestive diseases, long-term consumption of large amounts of protein or too much protein decomposition and other factors can cause malnutrition edema.