Fasting blood sugar of 10.3 mmol/L is more serious. For undiagnosed people, diabetes can be diagnosed if accompanied by diabetic symptoms; for diagnosed diabetics, it is a failure to control sugar. All are more serious cases. The reference value of normal fasting blood glucose is 3.9~6.0mmol/L, 6.1~6.9mmol/L is impaired fasting blood glucose regulation, ≥7.0mmol/L can be diagnosed as diabetes when diabetic symptoms occur at the same time. Therefore, 10.3mmol/L is more serious, and should be timely medical treatment, combined with clinical symptoms to diagnose diabetes, early intervention and treatment. For diabetic patients, the goal of glycemic control is generally in the fasting blood glucose 4.4mmol / L ~ 7.0mmol / L, 10.3mmol / L belongs to the glycemic control does not meet the standard, long-term poor glycemic control may lead to diabetic nephropathy, diabetic retinopathy and other complications, which is more serious. If you have elevated fasting blood glucose, it is recommended that you consult a doctor in time to clarify the cause of the disease and carry out targeted treatment or therapy with the help of your doctor.