Oral test (75 grams of )

Your doctor has asked you to have an oral hyperglycemia test (75 grams of glucose). This fact sheet describes the purpose of the test, what it involves, and how to prepare for it.

What is this test for? How do I prepare for this test? It is used to confirm the diagnosis of , > During the 3 days before the test, eat as you , or glucose intolerance. usually do. Don’t change your habits. > Some medications may distort the test What does this test involve? results. If you are taking any medications, please consult your doctor to find out if you It consists of measuring the blood sugar should stop taking them before the test. After concentration after drinking a drink called the test, you will be able to start taking your Glucodex, which tastes sweet and contains normal medications again. Bring them with 75 grams of glucose. The test requires 2 or you to the hospital on the day of the test. 3 blood samples, depending on your case: 2 blood samples Where do I go for this test? 3 blood samples (in cases of pregnancy) Go to the CHUM Test Centre, between 7 a.m. and 9 a.m., Monday to Friday. Be sure to bring Do I need to be for this test? your doctor’s prescription. > 514 890-8349 Yes. You must not eat or drink anything for 8 hours before the test. However, you can continue to drink water. 4 005 454 655 - June 2016 Oral hyperglycemia test 1 Health Literacy Center How long does this test take ? Are there any precautions to be It takes about 2 hours and 30 minutes. This taken DURING this test? is the time required for the drink to be well > During the 2-hour waiting period, you may digested and to take the blood samples. not eat, drink, or smoke. However, allow a little more time in case there > You must remain seated in the waiting room. is a wait. Exercise increases sugar . > You cannot go to another appointment. How is this test done ? > You can go to the toilet to urinate if 1 A blood sample is taken from a vein in your necessary. arm to find out your baseline blood sugar > You can chew sugar-free gum. level. 2 You are then given the Glucodex drink in a When will I get the results? glass. You need to drink it within 5 minutes. 3 If you are having 2 blood tests: a second Your doctor will give you the test results at blood sample will be taken 2 hours after you your next visit. finish the drink. Reminder: the day of your test, don’t If you are having 3 blood tests: 1 hour after forget to bring: drinking the drink, a second blood sample will be taken. Then you will wait 1 hour for a Your valid Quebec health third blood sample to be taken. insurance card (check the expiration date) 4 The tubes of blood will be sent to the laboratory for analysis.

Usually this test is well tolerated. Let us know if you feel uncomfortable. Some USEFUL RESOURCES people have heartburn or . If you vomit the Glucodex drink, the test Other health sheets published by the will be cancelled. The professional will CHUM are available. Ask for those that give you back your prescription and ask might fit your situation. you to come back another day.

You can also find them on our web site chumontreal.qc.ca/fiches-sante

The content of this document in no way replaces the recommen­ ­dations and diagnoses made, or the treatment suggested by your health professional.

To find out more about the Centre hospitalier de l’Université de Montréal chumontreal.qc.ca

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