Patients with high blood glucose may experience symptoms such as excessive drinking, excessive eating, excessive urination, weight loss, dehydration, nausea, etc. Some patients’ symptoms are not obvious. Clinical fasting blood glucose normal value is 3.9~6.1mmol/L, 2 hours after meal normal value is less than 7.8mmol/L. When blood glucose is higher than normal value, it is high blood glucose. High blood glucose may appear polyuria, thirst, drinking, eating, weight loss, dehydration, nausea, vomiting and other symptoms, the main reason is that increased blood glucose can trigger osmotic diuresis, but also stimulate the hypothalamus triggered by the symptoms of thirst, while the body glucose utilization is reduced, which will cause the body to consume too much protein and fat, resulting in weight loss, which caused by a series of symptoms. Some of the patients with high blood sugar early symptoms are not typical, found that elevated blood sugar, it is recommended to go to the hospital in a timely manner to clarify the cause, the condition of blood sugar control under the guidance of the doctor.