A healthy or normal blood sugar is between 70 and 100 if the person has not eaten (known as a fasting blood glucose level), according to Medline Plus. If taken after eating, a normal blood sugar level is typically below 125.
A fasting blood glucose level between 100 and 125 suggests prediabetes, which increases the risk of developing type 2 diabetes, according to MedlinePlus. A fasting blood sugar level of 126 or higher usually indicates diabetes. Nonfasting (also known as random) blood glucose levels of 200 or higher often mean diabetes. Follow up can include a fasting blood glucose test, a glucose tolerance test or an HbA1c test.