High Blood Glucose Levels Doctors diagnose diabetes on the basis of too-high levels of glucose in the blood. If you have diabetes, your blood glucose levels rise because of the foods you eat.
Foods have little effect on blood glucose in people without diabetes.
Normally, insulin, a hormone that is made in the pancreas, allows glucose to enter your body s cells and be used as fuel. Insulin is the main tool your body uses to lower your blood glucose level. Instead, their unused glucose builds up in their blood and passes through the kidneys if the glucose level becomes high enough. What Urine Tests Measure High urine glucose levels give doctors a clue that something is wrong. But urine tests are not a good way to diagnose diabetes.