Diagnosis of Diabetes

A diagnosis of diabetes can be confirmed by a series of tests that might include:

• A blood test that measures the glucose in your blood. A blood glucose level of 200 milligrams per deciliter (mg/dL) or greater, with symptoms, means that you have diabetes.

• A blood test for glucose after you have fasted, called fasting plasma glucose (FPG) value. An FPG value of 126 mg/dL or greater means that you have diabetes.

• A measurement of glucose in your blood through an oral glucose tolerance test (OGTT). Although this test is no longer recommended because it is cumbersome, some health care providers may still use it. After fasting, you have to drink a glucose syrup and have a blood sample taken 2 hours later. An OGTT value of 200 mg/dL or greater means that you have diabetes.

People with test results between "normal" and "diabetes" levels have impaired glucose metabolism and are at risk for developing diabetes, heart attacks, and strokes.