You are here: Deaconess Hospital > Deaconess Hospital Services > Laboratory > Patient Information > Glucose Tolerance Test Information

Glucose Tolerance Test: Information for Patients


Your doctor has requested a glucose tolerance test, which involves assessing how your body handles an intake of glucose. The purpose of the test is to see if you have sugar diabetes. The procedure involves taking a blood sample from your arm when you arrive for your appointment. The sample is taken to the laboratory, where the blood sugar level is measured. Some patients may not require the second part of the test and will be sent home. Most patients will be asked to drink a sugary liquid. You should drink this all within five to ten minutes, and then you will then be asked to sit quietly until it is time to have more blood drawn. Blood will be drawn from your arm at certain times, according to your doctor’s test order. We ask that you not smoke, eat or drink anything but water during the test.

What are the risks, consequences and alternatives associated with having the procedure? 

A few patients may suffer headaches after drinking the sugary liquid. Some people may feel sick or actually be sick. If you become ill, we must contact your doctor and cancel the test. If you should have any questions or concerns, please contact your doctor prior to your test.

Getting ready for the procedure

After 11:00 pm on the night before the test you must not eat. Drink enough fluid to avoid feeling thirsty. Do not eat anything on the day of the test. Please consult your doctor about taking any medications the day of your test. You should expect the test to take approximately three or more hours. Smoking is not allowed. We suggest you bring something to read to pass the time.

What should I expect after the procedure?

There should be no pain following the test. The sugary drink makes some people feel a little sick, but this should pass within an hour or so. You can eat and drink normally when you leave the hospital, but you must not eat prior to or during the test. You should expect to return to your normal activities when you leave your appointment.

What happens when I leave my appointment?

You will not need any further time off from work/school and should be able to return to what you would normally be doing on that day. The results of the test will be sent to your doctor, and he or she will let you know whether you need any follow-up appointments.

If you need to cancel your appointment... 

Deaconess Regional Lab – Deaconess Hospital Campus
600 Mary St., Evansville, IN 47747    Office: 812-450-3440

Deaconess Regional Lab – Mary St.
520 Mary Street, Suite 330, Evansville, IN 47710    Office: 812-450-1655

Deaconess Regional Lab - Newburgh
4133 Gateway Blvd. Suite 110, Newburgh, IN 47630    Office: 858-6255

Deaconess Gateway Hospital Outpatient Lab
4011 Gateway Blvd., Newburgh, IN 47630    Office: 812-842-3447