How well your body can metabolise glucose is determined by the glucose tolerance test. Your body requires glucose, a specific form of sugar    to fuel its cells. The food you eat is converted by your body into glucose, which then enters your bloodstream. Your pancreas produces the hormone insulin, which aids in delivering bloodstream glucose to your bodys cells. The glucose levels in your blood will be too high if your bodys cells are unable to receive insulin, a condition known as insulin resistance, or if your body is unable to create enough insulin. The glucose tolerance test can be performed in conjunction with other tests to identify or confirm prediabetes and diabetes by determining how your body processes glucose.