Glucose Tolerance Test

(OGTT)

What

The glucose tolerance test, also known as the oral glucose tolerance test, measures your body's response to sugar (glucose). The glucose tolerance test can be used to screen for type 2 diabetes.

Why

The glucose tolerance test identifies abnormalities in the way your body handles glucose after a meal — often before your fasting blood glucose level becomes abnormal.

Preparation

You are required to fast, consuming no food or liquids other than water, for 8 hours before the test.