Diagnosing Diabetes.

Diabetes has few symptoms until it is in advanced stages. Symptoms of diabetes may include excessive urination, frequent thirst, and a dry mouth.

The preferred diagnostic screening test for type 2 diabetes is a blood sugar test called the fasting plasma glucose test, in which a blood sample is taken to assess blood sugar levels.

Your healthcare provider will probably have you fast before taking a blood sugar test because foods and beverages can affect blood sugar levels. Some nutritional supplements and medications can also affect your blood sugar.

In a fasting blood sugar test, a test result of 80 to 110 is considered normal, while results between 110 and 125 suggest a person is at risk of developing diabetes in the future. Levels higher than 125 indicate the presence of diabetes, and the test must be repeated at a later date to confirm the diagnosis.

Another test that measures blood sugar levels is the hemoglobin A1c (HbA1c) test. This test can indicate blood sugar levels over a period of time, while the typical blood sugar test measures blood sugar levels only at a specific point in time.

The HbA1c test measures how much glucose in your blood stream has become bound to hemoglobin. Since blood cells last for about 90 days, the test can indicate how much glucose has been in the blood stream for the past one to three months.

People who do not have diabetes should have HbA1c levels of about 3 percent to 6.5 percent. If you have diabetes, you should aim for HbA1c levels of about 8 percent.