Diabetic complications are divided into acute and chronic complications. Acute complications mainly include diabetic ketoacidosis and hyperosmolar hyperglycemia syndrome, while chronic complications mainly include microangiopathy, neurological complications, and diabetic foot. 1. Acute complications include diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome. (1) Diabetic ketoacidosis is mainly characterized by hyperglycemia, ketosis and acidosis, with clinical manifestations such as deep and rapid breathing and the smell of rotten apples in the expiratory breath. (2) Hyperosmolar hyperglycemia syndrome is mainly characterized by hyperglycemia, high osmolality, and dehydration, with a slow onset, and dehydration and neuropsychiatric symptoms may gradually appear. 2. Chronic complications include microvascular lesions, neurological complications, and diabetic foot. (1) Microangiopathy includes diabetic nephropathy, diabetic retinopathy, diabetic cardiomyopathy, typical changes in microcirculation disorders, with clinical manifestations such as decreased glomerular filtration rate, decreased visual acuity, heart failure, arrhythmia and so on. (2) Neurological lesions most often involve peripheral nerves, characterized by abnormal sensation, pain, and nociceptive hypersensitivity at the extremities, and electrophysiological findings of slower motor and sensory nerve conduction velocity. (3) Diabetic foot is characterized by foot ulcers, deep tissue destruction, infection, and abnormalities of the distal nerves of the lower extremities. If diabetic complications are suspected, you should seek prompt medical attention for examination and treatment under the guidance of your doctor.