Diabetes Diagnosis – In A Nut Shell!

diabetes diagnosis

Diabetes diagnosis can be tricky. Diagnosing the disease depends somewhat on what type of diabetes you may have. Let’s take a look at each type and see how it is done.

One of the following three tests (now four!) is used.

Fasting Blood Glucose Test.
Diagnosing type 1 and type 2 diabetes is usually done using the fasting blood glucose test. This diagnosis test is the preferred method for non-pregnant adults and children. A positive result is a blood glucose level of 126 milligrams per deciliter (mg/dL) or more after an eight hour fast. This test is most accurate if conducted in the morning. A positive result for this, and most other diabetes tests, is only made after a confirming test is conducted on a different day.

Oral Glucose Tolerance Test (OGTT).
This test is less common for diagnosing type 1 and type 2 diabetes. A blood glucose level of 200 mg/dL or more, 2 hours after drinking a 75 gram glucose enriched beverage, is considered a positive result for diabetes. Again, any positive result would be retested on a different day.

Random Test.
This diabetes diagnosis test is also less common. The test can be conducted at any time of day (hence the “random” name) and a blood glucose level of 200 mg/dL or more is considered a positive diagnosis. However, this test is not a positive result unless there are also other diabetes symptoms.

2010 update-a1c test is a new diabetes Diagnosis option

At the beginning of 2010, the Americans Diabetes Association (ADA) decided that the A1c test is now appropriate for diagnosing diabetes. The new guidelines were issued in the Clinical Practice Recommendations for 2010. The hope is that more people will be diagnosed because the A1c does not require a fast before taking.

It is thought that many people avoid the other diagnostic tests because they require a fast. It is estimated that up to 25 percent of all diabetics are undiagnosed.

the guidelines state that people without diabetes will normally have a reading around 5 percent. People with pre-diabetes will have a reading between 5.7 and 6.4 percent. Lastly, a reading of 6.5 percent or higher will be diagnosed as having diabetes.

Diabetes gestational diabetes

diagnosis of diabetes

Diagnosing Gestational Diabetes is done using a form of the Oral Tolerance Glucose test. During pregnancy, blood glucose levels are typically lower than normal. Accordingly, the glucose testing threshold levels are adjusted lower.

The woman’s blood glucose level is taken prior to starting the test. Next, she drinks a glucose solution, and then her blood glucose is measured in 1, 2 and 3 hour increments afterwards.

Gestational diabetes is positive if two or more of the four samples measure greater than the following:

  • Initial Test is 95mg/dL or greater.
  • 1 Hour Test is 180 mg/dL or greater.
  • 2 Hour Test is 155mg/dL or greater.
  • 3 Hour Test is 140 mg/dL or greater.

Check with your doctor to see if one of these diagnosis tests are right for you.


ADA Clinical Practice Recommendations 2012 (Accessed January 2012)