Regardless of fasting or postprandial blood glucose 27.7mmol/L, it is generally a more serious condition, which may lead to serious complications such as ketoacidosis, and prompt medical attention is recommended. Normal fasting blood glucose should be 3.9-6.1mmol/L. Fasting blood glucose ≥7.0mmol/L with typical diabetic symptoms can be considered for diagnosis of diabetes. Postprandial 2-hour blood glucose should be <7.8mmol/L, ≥11.1mmol/L with typical diabetic symptoms can be considered to diagnose diabetes mellitus. Whether it is fasting or 2 hours postprandial blood glucose, 27.7mmol/L is a very high blood glucose value. A blood glucose of 27.7 mmol/L is very likely to lead to serious metabolic disorders, and acute complications may occur, such as ketoacidosis, leading to circulatory failure, acute renal failure, and in severe cases, psychiatric disorders. It is recommended that people with very high blood glucose values seek prompt medical attention and follow medical advice.