Diabetic patients usually have no special clinical symptoms in the early stage, with the development of the disease may appear polyuria, polydipsia, polyphagia and weight loss symptoms, if not actively treated, the late stage of the disease may appear a variety of acute and chronic complications, acute complications include diabetic ketoacidosis, chronic complications more, such as diabetic nephropathy, retinopathy, cardiovascular lesions, neuropathy, and so on. Typical symptoms of diabetes mellitus are “three more and one less” associated with high blood glucose and symptoms and clinical manifestations such as skin infections, fatigue, vision changes, etc. However, many patients in the early stages of the disease are often asymptomatic or have mild symptoms. As the disease progresses, patients with diabetes will gradually develop multi-system damage and clinical symptoms associated with complications. Acute complications: typical symptoms of diabetic ketoacidosis include nausea, vomiting, and the smell of rotten apples on the exhaled breath; hyperosmolar hyperglycemia syndrome is characterized by a sharp rise in blood glucose, accompanied by severe water loss and even coma. Chronic complications: diabetic nephropathy may appear double lower extremity edema, foamy urine and other symptoms; retinopathy may appear vision loss and other symptoms; diabetic cardiovascular disease will appear arrhythmia, atherosclerosis and other diseases; may also appear diabetic foot, manifested as foot ulcers, infections and other symptoms. The symptoms of diabetes mellitus are complex and varied, so if you feel unwell, please go to the hospital.