One of the first tests someone may have if diabetes is suspected is a simple urine test.
Normally the urine does not contain glucose, but in diabetic people some glucose can overflow from the kidneys into the urine.
Urine is also tested for ketones (an acid remaining in the body when it burns its own fat). When the body is not producing any insulin it starts to burn fat for energy and ketones are then released into the bloodstream.
This problem is more typical of type 1 diabetes.
A Fasting Blood test
A fasting blood test can confirm a diagnosis of diabetes. You should not eat or drink anything other than water for 8-10 hours prior to the test.
The Hb1Ac test is a blood test that is used in the diagnosis of diabetes and also used to monitor the management of the condition.
It is now recommended that HbA1c can also be used as a test to diagnose diabetes. An HbA1c value of 48 mmol/mol (6.5%) or above is recommended as the blood level for diagnosing diabetes. A value of less than 48 mmol/mol (6.5%) does not exclude diabetes diagnosed using glucose.
This test cannot be performed on certain people, for example children or pregnant women.
Glucose Tolerance test (GTT)
Also called an oral glucose tolerance test.
This test examines how well the body deals with glucose. You should not eat or drink anything other than water for 8-10 hours prior to the test. A blood test is then taken, and then a glucose drink is given followed by another blood test, usually 2 hours later.
After your glucose tolerance test is complete it should be possible to determine whether you have impaired glucose tolerance (IGT) or diabetes, based on the amount of glucose in your blood both before and after drinking the glucose drink.
Please note that this test is now used much less frequently but may be used in certain situations, such as diabetes developing in pregnancy.