The glucose tolerance test is a laboratory method to check how the body breaks down (metabolizes) sugar.

How the Test is Performed

The most common glucose tolerance test is the oral glucose tolerance test (OGTT). You cannot eat or drink anything after midnight before the test. For the test, you will be asked to drink a liquid containing a certain amount of glucose. Your blood will be taken before you do this, and again every 30 to 60 minutes after you drink the solution. The test takes up to 3 hours. Continue reading →