Typical symptoms of diabetes mellitus are “three more and one less”, i.e., excessive drinking, excessive urination, excessive eating, and weight loss. There is individual variability in the clinical symptoms of diabetes mellitus, which may vary from patient to patient. Diabetes mellitus patients with elevated blood glucose due to osmotic diuresis caused by polyuria, followed by thirst and polydrinking; peripheral tissues of glucose utilization disorder, increased lipolysis, protein metabolism negative balance, can be seen in fatigue, emaciation, children’s growth and development of the obstruction; patients often have easy to hunger, overeating. In addition to the above typical symptoms, some patients may have skin itching, especially vulvar itching. When the blood sugar rises faster, it can make the ocular fluid and lens osmotic pressure change and cause refractive changes resulting in blurred vision. Patients with diabetes should seek medical treatment as soon as possible when the above symptoms occur.