Diagnosis of Diabetes

Diabetes diagnosis is typically confirmed by a doctor using a blood glucose test. However, early suspicion of a possible diabetes diagnosis may arise from either its symptoms, the symptoms of its complications (e.g. leg rashes), or by a screening test.

Diagnostic Tests for Diabetes: The main diagnostic tests for diabetes include:

  • Urine glucose test. This is a test for sugar (glucose) in the urine. Normal urine does not contain glucose. High blood sugars from diabetes will cause sugar to unexpectedly appear in the urine. A positive result for sugar in the urine is a strong indicator that you have diabetes, but itís usually confirmed by a blood sugar test as well. A negative result for sugar in the urine doesnít necessarily mean that you donít have diabetes, although you probably donít have the most severe high blood sugars yet, and your doctor may still ask for a blood glucose test to fully check for diabetes. You could also still have pre-diabetes even if a urine sugar test is negative.
  • Blood glucose test (venous blood). This is the main confirmation test for diabetes. It is a full blood test, with blood drawn from a vein; it is not a finger-prick blood drop test. Your blood sugar level gives a good indication as to whether you have pre-diabetes, diabetes, or you donít have diabetes. There are also subtypes of blood glucose test, such as fasting blood glucose test versus a random blood glucose test. A fasting blood glucose test is a better test for diabetes than a random test.
  • Blood glucose finger-prick tests. These finger-prick blood tests of a blood drop for glucose levels are reasonably accurate. Your doctor might do a finger-prick test in their office, or you might also do a finger-prick test at a diabetes screening day. Depending on the level of glucose in the blood drop, it can be a strong indicator of whether you have diabetes, pre-diabetes, or no diabetes. Your doctor will usually order a full blood glucose test to confirm the results seen in a finger-prick test.

Other Blood Sugar Tests. Some of the other tests commonly used for diabetics, but not really for initial diagnosis, include:

  • HbA1c blood test. This is a form of blood glucose level test that gives a kind of average of your blood sugar levels over the last few weeks or months. Although newly diagnosed diabetics will often have a high value, this test is not really used for diagnosis of diabetes. It is mainly used for tracking long-term blood sugar control as part of managing diabetes.
  • Fructosamine test: This is another form of average blood glucose test. However, it gives an indication of blood sugar levels over a shorter period than HbA1c tests.

Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.