There are many factors affecting blood glucose, diabetic patients who are receiving glucose-lowering treatment have unstable blood glucose all the time, and need to find the following reasons: 1, diet, diabetic diet needs to be timed, quantitative, regular meals, when eating too much, too little or delayed meals, it is easy to lead to excessive fluctuations in blood glucose. 2, exercise, exercise can promote calorie consumption, improve insulin resistance, which is conducive to diabetic patients to control blood glucose, but the amount of exercise is also easy to cause patients to have hypoglycemia. Excessive exercise can also easily lead to hypoglycemia, so diabetic patients should choose the appropriate form of exercise, exercise intensity and exercise time according to their own situation.3. Pancreatic β-cell function, when diabetic patients have poor pancreatic β-cell function, such as type 1 diabetes or type 2 diabetes with a long duration of the disease, the ability to regulate blood glucose is poor, which can easily lead to unstable blood glucose.4. Other, such as emotions , sleep, women’s menstrual period and co-infections and other diseases, will affect the control of blood glucose, resulting in unstable blood glucose.