During the oral glucose tolerance test your blood glucose is tested two hours after drinking 75 grams of glucose. You are diagnosed with diabetes if your blood glucose level is 200 mg/dl or greater.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.