According to data released by the International Diabetes Federation (IDF) in 2019, there are about 116 million people with diabetes among adults aged 20-79 in China, the highest in the world. What is inconsistent with the high prevalence of diabetes is that the diagnosis rate of diabetes is only 30-40%, and undiagnosed diabetes patients account for 63% of the total. So what is it that causes such a high rate of underdiagnosis of diabetes? Today I will walk you through what you need to know about prediabetes. Prediabetes includes impaired fasting glucose (IFG) and abnormal glucose tolerance (IGT). If fasting blood glucose is ≥6.1mmol/l and <7.0mmol/l, it is called impaired fasting blood glucose; if two hours after meal blood glucose is ≥7.8mmol/l and <11.1mmol/l, it is called abnormal glucose tolerance. Patients who have both high fasting glucose or high postprandial glucose have a higher risk of developing diabetes than those who have both. Up to now, many units still check fasting blood glucose to rule out diabetes, unaware that the rate of pre-diabetes and diabetes missed due to missed postprandial blood glucose is very high. Most patients with pre-diabetes can be reversed to normal blood glucose after scientific intervention. If left unattended, many people develop diabetes after 1-2 years. We suggest that pre-diabetic patients actively consult the endocrine metabolic clinic and perform 75gOGTT test if necessary to clarify the presence of diabetes. We believe that through scientific and correct guidance, you will step into a healthy blood sugar life again.