Ketoacidosis is a diabetic emergency with hyperglycemic ketosis and acidosis as the main manifestations. The most common cause is infection, such as upper respiratory tract infection, lung infection, acute pancreatitis, cholecystitis, pelvic inflammatory disease and urethritis. Other common causes of ketoacidosis include sudden interruption or inappropriate dose reduction during insulin therapy, various stressful stimuli such as surgical trauma, fracture, myocardial infarction, alcoholism, glucocorticoid medication, and excessive consumption of sugar and fatty foods. Patients should apply glucocorticosteroids under the guidance of a doctor, especially when an infection first appears, and must pay attention to monitoring blood glucose, observing blood glucose fluctuations, and going to the hospital for further treatment when necessary. The usual diet should be regular and quantitative, and no food with too much sugar should be consumed at will.