The main cause is commonly seen in patients with type 1 diabetes or type 2 diabetes with very poor islet function, where interruption of insulin therapy or insufficient insulin doses can cause ketosis; secondly, it is also seen in various kinds of stress (such as trauma, major surgery, or severe infection), which often induces ketosis; thirdly, excessive dieting or low-energy diets often cause ketosis. So how do you need to identify it? The fact is that blood ketones are the standard. When there is no condition to detect blood ketones, the main observation of symptoms, signs and other laboratory tests are important reflective indicators. Generally early and middle stage clinical manifestations such as fatigue, loss of appetite, nausea, vomiting, decreased urine output, dry mouth, headache, a few patients show abdominal pain, changes in vital signs such as red face, dehydration signs, deep and fast breathing in acidosis, rotten apple smell in exhaled breath, decreased blood pressure, accelerated heart rate, and cold extremities, etc. In the late stage, there can be different degrees of impaired consciousness. When such symptoms appear, pay attention to hospital examination as soon as possible. Laboratory examination, for patients with random blood glucose over 13.9mmol/L glucose quiet disease, urine ketone should be repeatedly tested, and blood gas analysis should be checked if necessary, in order to clarify the diagnosis of diabetic ketosis and ketoacidosis as early as possible.