A recent blood test has found that you have a slightly raised level of glucose (sugar) in your blood. To find out if this is a normal result or if you have diabetes, we need to do a further test called a glucose tolerance test. This test will measure the glucose levels in your blood after fasting and again 2 hours after having had a glucose drink.

Although you may not eat a lot of sweet foods, most of the food that you eat is converted into sugars to be taken by your blood to other parts of the body, to be used for energy.

On the days before the test, do not alter your normal diet as this may affect the result of the test.

For the test, you will need to have nothing to eat or drink from 9pm the night before your test and have no breakfast the next morning, though you may have a drink of water. You must not have any food or drink other than water from 9pm the night before the test, until the test is complete.

The morning of your test you will have a blood test taken and after this you will be given a lemon flavoured drink of glucose. You must continue not to have anything else to eat or drink for a further 2 hours. You are advised to rest quietly until the second blood test, maybe bring a book to read!

Two hours after the glucose drink another blood test will be taken. You will then be able to go home and have your breakfast! We should have the results of the test for you 5 days later, you will be asked to phone the receptionists (after 11am) to get the results, unless the doctor or nurse has already arranged to see you again.