1. Factors affecting the increase of blood glucose in malignant tumor patients (1) Stress factors: Serious disease state can cause strong stress reaction, which leads to serious material and energy metabolism disorder of the body, and when multi-organ failure occurs, the rate of glucose production exceeds the rate of glucose clearance is the main reason for stress hyperglycemia. (2) Age factor: The chance of malignant tumors is much higher in elderly people over 60 years old than in young people. Diabetes and its complications have become the main cause of death after cardiovascular and cerebrovascular diseases, and have become a major health problem for the elderly, which must be given great attention. (3) Nutritional intake: Both parenteral and enteral nutrition with excessive sugar intake can cause hyperglycemia. The lack of exercise for long time bedridden patients and the decrease of sugar conversion in the body make the increase of blood sugar more obvious. Malignant tumor patients have lower metabolic function and weakened physical activity, especially diabetic patients should control their diet, not to overeat, and should change the habit of sleeping after eating to avoid digestive disorders and coronary heart attack. Avoid eating dessert, less fried, pickled or overheated and cold food, and prefer to eat light and soft food which is good for digestion and absorption. 2. The harm of high blood sugar to malignant tumor patients Elevated blood sugar will affect the body’s autoimmune function, and high blood sugar is an important factor that aggravates the body’s energy metabolism disorder. Chemotherapy drugs have great damaging effect on normal tissues including pancreas, causing reduction of insulin secretion, aggravating metabolic disorder of diabetes and even endangering life. Therefore, for patients with malignant tumor chemotherapy, blood sugar control is the key to success or failure of chemotherapy. 3.Specific method of blood glucose control Monitoring blood glucose: whether to take a correct and strict method to monitor blood glucose will affect the implementation effect of specific blood glucose control program. When using 75% alcohol to disinfect the skin, it is necessary to wait until the skin at the end of the finger is dry before collecting blood, otherwise the water will dilute the blood, and the alcohol will also affect the oxidase on the test paper, which will lead to inaccurate measurement values. In addition, there are differences in blood glucose values between the finger ends of different fingers. Therefore, patients who need to monitor blood glucose value should collect blood from the same fingertip relatively regularly for a period of time. Blood collection is generally preferable at the thin skin of the corner of the nail at the tip of the ring finger of the left hand. Blood glucose control: (1) Blood glucose control in case of emergency: clinically, insulin is the drug of choice for rapid normalization of blood glucose. When patients cannot eat, ketosis, coma, infection and multiple organ failure, it is difficult to achieve the purpose of intensive insulin treatment by subcutaneous injection, and intravenous drip must be used. (2) Control of blood sugar in chemotherapy patients: monitor the end blood sugar before three meals and at bedtime during and after chemotherapy, and adjust the dose of oral hypoglycemic agents or Novocain according to the end blood sugar. (3) Pay attention to hypoglycemic reaction: It is very important to prevent the occurrence of hypoglycemia for patients with severe disease, if the blood sugar <2.2mmol/L, it can lead to irreversible damage to the nervous system, so it is very important to detect and correct hypoglycemia quickly. Once the patient is found to be hungry, cold sweat, irritable and other hypoglycemic manifestations, glucose injection should be given immediately or food with high sugar content should be eaten. When elderly people go out, carry sweet food and first aid card with them. Mobilize the initiative of malignant tumor patients and their families to make them understand the danger of long-term hyperglycemia and its complications, and realize the preventability and treatability of diabetes and the danger of not preventing and not treating it. To do strict control of diet, appropriate amount of exercise, reasonable drug treatment, active detection and prevention of complications. Paying attention to psychological care is also one of the key aspects of treating malignant tumor patients. In the treatment process of tumor patients with combined diabetes, if the blood sugar control is not satisfactory, it indicates poor prognosis of tumor. Good and effective control of blood glucose enables malignant tumor patients to enhance self-care ability, improve body function, effectively reduce complications, and then improve quality of life. At the same time, the compliance of patients receiving treatment and care is enhanced, avoiding hospitalization or shortening the hospitalization time as much as possible and reducing the burden.