The document defines and describes the glucose tolerance test (GTT), also known as the oral glucose tolerance test (OGTT). It provides information on: - Indications for the GTT include diagnosing diabetes in doubtful cases, during pregnancy with risk factors, and to rule out renal glycosuria. - Contraindications include confirmed diabetes and using it for follow-up rather than initial diagnosis. - The test involves fasting overnight, drinking a glucose load, and having blood samples taken at baseline and 2 hours to measure the blood glucose response. - Normal values are a fasting blood glucose below 110 mg/dL and a 2-hour post-load value below 140 mg/dL. Higher values meet