Description of the service

Impaired glucose tolerance is a disorder of the sugar metabolism in which the body’s ability to handle the amount of glucose that comes with food is impaired, but when fasting, glucose stays within normal limits. Even if blood glucose is normal when fasting, the amount of carbohydrates from food is too large for the body, and blood sugar increases too much. This can be examined with a glucose tolerance test.

Comply with instructions and set aside two and a half hours for your visit.

Preparing for the test

  • General

    The test measures your body’s ability to balance your blood sugar levels after you have enjoyed food or drinks containing sugar.
    Avoid physical strain immediately before and during the test.
    To ensure that the test result is reliable, you should eat enough carbohydrates (bread, potatoes, sugar) on the days before the test.

  • Can I have a normal evening snack on the day before the test?

    You can and you should. Fasting for too long will interfere with the test. Before the test, you should not eat or drink for 10 to 14 hours. The only exception is a glass of water.

Glucose tolerance test

  • What happens during the test?
    • After a blood sample has been taken, you will be given a glucose solution to drink. The solution must be drunk within approximately five minutes.
    • Blood samples will be taken either 1 and 2 hours or just 2 hours after you have finished the glucose solution. The samples will be taken from a vein or from a finger prick, each time in the same way.


  • Who will interpret my results?

    Please note that the doctor treating you is always responsible for interpreting the results. Consult your doctor if you have any questions regarding the test results.