Diabetic patients can drink more plain water, which is beneficial to their health, because diabetic patients will produce the effect of osmotic diuresis due to the rise of blood sugar, that is, patients appear polyuria, thirsty symptoms, drinking more plain water can improve the situation of water shortage in the body of patients to a certain extent. Some patients with high blood glucose due to the combination of diabetic ketosis, drinking more water is conducive to the excess ketone bodies in the blood from the urine out of the body, to achieve the purpose of correcting the treatment of ketosis. Diabetic patients with high blood sugar, blood in a relatively high coagulation state, the risk of cardiovascular disease is relatively high, by drinking plain water can make the blood hypercoagulable state effectively improved, reducing the risk of cardiovascular disease.