Diabetes can be diagnosed with fasting or 2-hour postprandial glucose of 15 mmol/L. Its survival is related to the presence or absence of complications and glycemic control, and the specific survival period varies from person to person, but those with good control and no complications usually do not affect life expectancy. Diabetes can be diagnosed with fasting blood glucose ≥7.0mmol/L or 2 hours postprandial blood glucose ≥15mmol/L. Diabetes itself does not affect the life expectancy of patients. A fasting or 2-hour postprandial blood glucose of 15mmol/L all the time requires pharmacological intervention to control the blood glucose within the normal range, which can avoid complications and enable patients to live a healthy life. However, if the control is poor, acute or chronic complications may occur, such as ketoacidosis, hyperosmolar coma, coronary heart disease, various infections, etc., which can be life-threatening in serious cases and may lead to death in a short time if they are not treated timely and effectively. In conclusion, diabetic patients should pay attention to it, actively carry out diet, exercise and medication, while maintaining a good state of mind and controlling blood glucose is sufficient.