The most common glucose tolerance test is the oral glucose tolerance test (OGTT). After an overnight fast, a patient drinks a solution containing a known amount of glucose. Blood is obtained before the patient drinks the glucose solution, and blood is drawn again every 30 to 60 minutes after the glucose is consumed for up to 3 hours.
http://www.nlm.nih.gov/medlineplus/ency/article/003466.htm
Some Info:
http://www.healthatoz.com/healthatoz/Atoz/dc/tp/tporal.jsp
http://en.wikipedia.org/wiki/Glucose_tolerance_test
http://my.webmd.com/hw/being_pregnant/hw44896.asp
If you have a choice, choose the lemon-lime glucose drink-I think it's the least sweet-tasting. You will have to drink it very quickly.
I was very cold with chills and shaking the first two hours after the test. I was also very nauseated. They can provide warm blankets if you do get cold. I was sick for the rest of the day, I went home and slept. I was diagnosed with abnormal response and insulin resistance. I also have hypoglycemia (low blood sugar), which is the opposite of diabetes.
Take care. Hava good day!
Meri