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. So what is needed 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, attention should be paid 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. Ketoacidosis can be divided into 3 conditions according to its degree: mild, moderate and severe. Mild pH <7.3 or bicarbonate <15mmol/L; moderate pH <7.2 or bicarbonate <10mmol/L; severe pH <7.1 or bicarbonate <5mmol/L, the latter easily entering coma. The main symptoms of acidosis are: excessive drinking and urination, increased physical strength and weight loss; decreased appetite, nausea and vomiting; ketone odor similar to the smell of rotten apples may be present in the breath; decreased urine output, dry skin, sunken eyes; headache, dizziness, depression followed by irritability, drowsiness, coma, etc.