Oral glucose tolerance test

When is this performed?

• In some circumstances this is required to clarify if a patient has diabetes mellitus 
• This test is used in pregnancy in certain patients to investigate whether a patient has gestational diabetes mellitus 
• This test is also used to investigate a condition called reactive hypoglycaemia 
• This test is used to investigate if a patient has excess growth hormone in the body (acromegaly)

What does the test involve?

• The administration of a glucose orally and the taking of blood samples

Are there any side-effects?

• Usually none

How long does the test take and is admission to hospital required?
 

• The test may take 2-4 hours depending on the reason for performing it and does not usually require admission 

What should you tell your doctor? 

• If you have diabetes mellitus