If you experience symptoms of severe increased thirst, frequent urination, unexplained weight loss, increased hunger or tingling of your hands or feet -- your doctor may test you for diabetes. This article discusses the various diabetes tests used to diagnose the condition.
According to Diabetes UK there are currently 2.9 million people in the UK with diabetes and there are an estimated 850,000 people with diabetes who have the condition and don’t know it because there may be no warning signs. To confirm the diagnosis of type 2 diabetes, your doctor will order a fasting blood glucose test.
Fasting blood glucose test
The fasting blood glucose test (FBG) is the preferred method for diagnosing diabetes because it is easy to do, convenient, and less expensive than other tests.
How do I prepare for the blood glucose test?
Before taking the blood glucose test, you will not be allowed to eat or drink anything for at least eight hours.
What happens during the blood glucose test?
During a blood glucose test, blood will be drawn and sent to a laboratory for analysis.
What do the results of the blood glucose test mean?
Normal fasting blood plasma glucose is between 4 and 6 millimols per litre or mmol/l for people who do not have diabetes. The standard diagnosis of diabetes is made when two separate blood tests show that your fasting blood glucose level is greater than or equal to 7 mmol/l. If your fasting blood glucose level is between 6 and 7 mmol/l you may have impaired glucose tolerance. This is not diabetes, but may mean your body is not processing glucose properly.
If you have impaired glucose tolerance, or if you have a normal fasting blood glucose, together with risk factors for diabetes or symptoms of diabetes, your doctor may decide to do a glucose tolerance test (see below) to be sure that you do not have diabetes.
Random blood glucose test for diabetes
The random blood glucose test is another method of diagnosing diabetes. During the test, blood sugar is tested without regard to the time since the person's last meal. You are not required to abstain from eating prior to the test.
A blood glucose level greater than 11.1 mmol/l may indicate diabetes, especially if the test is repeated at a later time and shows similar results.
Oral glucose tolerance test for diabetes
The oral glucose tolerance test is yet another method used to detect diabetes, but it is usually only done during pregnancy to diagnose gestational diabetes or for someone who is suspected of having type 2 diabetes yet has a normal fasting glucose level. It can also be performed to diagnose pre-diabetes.