Whether it is fasting blood glucose or 2-hour postprandial blood glucose, blood glucose 19.3mmol/L is very serious. If it is at this value for a long period of time and is not controlled in time, it may further lead to diabetic ketoacidosis, hyperosmolar hyperglycemic syndrome, diabetic foot and so on. 1. Diabetic ketoacidosis: long-term blood glucose 19.3mmol / L easily lead to diabetic ketoacidosis, there will be nausea, vomiting, breathing faster, exhaled gas has rotten apple flavor. If left untreated, there may be severe dehydration, sunken eyes, lowered blood pressure, impaired consciousness or even coma in the later stage. 2. Hypertonic hyperglycemia syndrome: slow onset at first, initially manifested as loss of appetite, polyuria, polydipsia, followed by gradual onset of severe dehydration and psychoneurological symptoms, and gradual coma. Compared with diabetic ketoacidosis, water loss is more serious and neuropsychiatric symptoms are more prominent. 3. Diabetic foot: foot ulcers, infections or deep tissue destruction associated with distal nerve abnormalities in the lower limbs and varying degrees of peripheral vasculopathy, resulting in gangrene, which may require amputation in severe cases, or even result in systemic infections endangering lives. A substantial increase in blood glucose should be taken seriously, whether or not there are symptoms, should be timely medical care, to identify the causes of the sharp increase in blood glucose, symptomatic, cause-specific treatment, so as not to delay the condition.