Though not always, diabetes can occur with no symptoms. A blood test is used to identify whether or not you have the disease. A urine test may be looked at first to see if you have high blood sugar (too much glucose in the bloodstream), but the results of a urine test alone are not enough to hang a diabetes diagnosis on. Diabetes is a chronic disease that can damage the eyes, nerves, and kidneys, as well as increase risk of heart disease and stroke.

If a urine analysis shows that your blood sugar level is higher than 200 mg/dL this may signal to your doctor the potential for diabetes. At this point, your doctor may order one of these three blood tests: a Hemoglobin A1c Test, a Fasting Plasma Glucose Test, or an Oral Glucose Tolerance Test. Let’s take a look at the difference among these three blood tests.

Hemoglobin A1c Test (A1C)
This test will show your doctor what your average blood sugar level (also known as blood glucose level, or the amount of glucose in your bloodstream) has been over the three to four months prior to the reading. The general goal here is for the test to read below 7. A result of 5.6 percent or less is considered healthy; a result between 5.7 percent and 6.4 percent is considered prediabetes (which is a warning zone that indicates you are at risk for developing full-blown diabetes but haven’t yet and may not ever). Lastly, a result of 6.5 percent or higher is considered diabetes.

Fasting Plasma Glucose Test (FPG)
Before taking this test, you must fast overnight. Your blood sugar is then checked in the morning before eating. If the result of this test is below 100 mg/dL than you are considered healthy. If the result is between 100 and 125 mg/dL, this range is considered prediabetes. If, however, the result is 126 mg/dL or higher, a diabetes diagnosis is made.

Oral Glucose Tolerance Test (OGTT)
You will also fast overnight before taking this test. Your blood sugar will then be measured two times. The first time will be in the morning before eating. The second reading will occur two hours later after your finish a drink high in glucose (sugar). Levels below 139 mg/dL are considered healthy. Levels between 140 and 199 mg/dL are considered prediabetes. When your level reaches 200 or higher, you have diabetes.