A blood glucose test measures the amount of a type of sugar, called glucose, in your blood. Glucose comes from eating carbohydrates in food and is the main source of energy used by the body.
Normally, your blood glucose levels increase slightly after you eat. This increase causes your pancreas to release insulin so that your blood glucose levels do not get too high. Blood glucose levels that remain high over time can damage your eyes, kidneys, nerves, and blood vessels.
How to prepare for this test:
- Eat a regular diet that includes carbohydrates daily for three days prior to the test.
- Fast for at least 8 hours but not more than 14 hours the night before the test (make sure you drink water in order not to get dehydrated)
- Take all medications as prescribed by your physician but do not take your supplements the morning of the blood draw.
What can I expect when I get to the lab?
A total of 4 blood glucose specimens will be drawn as follows:
- A fasting glucose level will be drawn.
- A drink containing 75 grams of glucose will be given to you to drink.
- 3 additional glucose levels will be drawn at 1 hour, 2 hours and 3 hours after the drink has been administered.
You will need to remain at the draw facility and seated throughout the entire test. Please bring a book or other quiet activity to keep yourself occupied while you are waiting.