Glucose Tolerance Test

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. More commonly, a modified version of the glucose tolerance test is used to diagnose gestational diabetes — a type of diabetes that develops only during pregnancy. 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. 

A glucose tolerance test measures how well your body is able to break down glucose, or sugar. Those who suffer from diabetes (type 1) have trouble processing glucose because the body is not able to make an adequate supply of insulin. This test is also used to diagnose the presence of gestational diabetes and type-2 diabetes. Type-2 diabetes develops during adulthood, unlike type 1 diabetes, which occurs during childhood. Type 2 diabetes is the most common form of diabetes. In this type, your body either doesn't produce enough insulin, the hormone in the body that metabolize sugar, or the cells in your body are resistant to insulin.

Gestational diabetes is when a pregnant woman who is not a diabetic, has high blood sugar levels as a result of the pregnancy. Generally most healthcare providers recommend that all pregnant women be screened for gestational diabetes. Experts recommend this test to pregnant women who are between 24 and 28 weeks of pregnancy. This test is also recommended for anyone suspected of developing adult diabetes.

If your test shows that your glucose levels are higher than normal, you may be asked to test again on a different day. Higher-than-normal levels of glucose may mean you have pre-diabetes, diabetes, or gestational diabetes