Having blood taken is stressful and even more so for children. And stress, whether emotional or caused by illness, can change blood sugar levels without necessarily suggesting a blood sugar illness. Also to be considered: a patient does not normally have an empty stomach in case of a previously unplanned blood control session. If that is the case, blood sugar where the patient has not eaten previously has to be controlled. If it is still above the guideline of 130 miligrams per deciliter, then the urine needs to be control for glucose levels. If the levels are borderline or above, an oral glucose tolerance test is recommendable. For this, the child drinks a sugary liquid. Glucose levels are measured before he or she drinks, and then every 30 minutes over the next two hours. Further examinations are called for if the glucose levels remain above normal after this time.