Hyperglycemia is mainly seen in diabetes mellitus, the typical symptom is not seven, it is three more and one less, mainly refers to polyphagia, polydipsia, polyuria and weight loss. 1. Eating more: glucose cannot be effectively utilized, and the body lacks energy, leading to easy hunger and excessive eating. 2. Drinking more: elevated blood glucose leads to increased plasma osmolality, resulting in easy thirst and excessive drinking. 3. Polyuria: with the increase of water intake, blood volume will increase, together with osmotic diuresis, leading to polyuria. 4. Weight loss: impaired glucose utilization and increased breakdown of fats and proteins lead to weight loss. Other symptoms include atypical symptoms such as itchy skin and blurred vision. It should be noted that there can be no obvious symptoms in the early stages of diabetes. People with high blood sugar are recommended to be examined and treated under the supervision of a doctor.