Many people first learn they have diabetes through blood tests done for another condition or as part of a routine physical exam. But in some cases, diabetes may not be detected before damage to your eyes, kidneys or other organs has occurred. That’s why the American Diabetes Association recommends adults have a fasting blood glucose test at age 45. If the test results are normal, repeat the test every three years. If your results are borderline, have a fasting blood sugar test every year. Your health care provider may also test for diabetes based on your symptoms or risk factors.
Mayo Clinic Health System family medicine provider Steven Adamson, M.D., says, "Although the amount of sugar in your blood fluctuates, the range is relatively narrow," says . "After fasting all night, most people have levels between 70 and 100 milligrams of glucose per deciliter of blood (mg/dL). That’s the equivalent of about one teaspoon of sugar in a gallon of water. If you consistently have fasting glucose levels above 125 mg/dL, you likely have diabetes."
Dr. Adamson shares tests that can detect diabetes: