Prediabetes: a common condition in which the blood sugar level is higher than normal but not yet high enough to be considered diagnostic of diabetes. Prediabetes is considered to be a precursor of type 2 diabetes and increases a person's risk of developing type 2 diabetes, heart disease, or stroke.
Prediabetes can often be reversed (without insulin or medication) with lifestyle changes such as losing weight, and increasing physical activity. Weight loss has been shown to prevent or delay the onset of type 2 diabetes. In prediabetes, the fasting blood glucose level is 100 mg/dl or more, but less than 126 mg/dl (the level which is diagnostic for diabetes). Hemoglobin A1c (HbA1c) levels are another laboratory test for diabetes. HbA1c levels of 6.5% or greater are characteristic of diabetes, while levels from 5.7% to 6.4% suggest prediabetes.
Prediabetes has also been referred to as impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). While some people with prediabetes may experience at least some of the symptoms of diabetes, in most cases it does not cause specific symptoms. Therefore, many people are unaware that they have prediabetes.
REFERENCE: American Diabetes Association. "Diagnosing Diabetes and Learning About Prediabetes." Updated Sep 09, 2016.