Glucose Tolerance Test

A Glucose Tolerance Test is used to test for diabetes, hypoglycaemia and faults in sugar metabolism. The testees blood sugar level is tested at hourly intervals before and after the administration of a large quantity of glucose drink.

A GTT must be administered to a fasting patient so they are usually done early in the morning.

A standard GTT lasts for two hours and that is sufficient to diagnose diabetes, but sometimes a three, four or five hour test may be necessary to pinpoint a longer-term problem such as slow-acting hypoglycaemia.