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Diabetes Information

About Diabetes
What causes Diabetes
Do you have Diabetes?
Are you at risk for Diabetes?
Screening for Diabetes
Complications of Diabetes
Treating Diabetes

Screening for Diabetes

      Often, blood tests taken during a physical exam or those taken for other reasons detect the presence of diabetes. However, in some instances, diabetes remains undetected until it begins to cause damage to other organs, such as the kidneys. Experts generally agree that after the age of 40, fasting blood glucose tests should be completed. If the tests are normal, they should be done every three years from that point forward. If the tests show heightened blood glucose levels, the tests should be done yearly. It can be important for patients to request these tests, as they are not always included as a routine test carried out during a physical exam. Talk to your doctor about these tests and your potential risk factors.

Although blood sugar levels fluctuate to some degree, fasting blood glucose tests can determine if your level is in the acceptable range. After fasting overnight, the normal range for blood glucose levels is 70-110 mg/dL (milligrams of glucose per deciliter of blood). If your fasting glucose level is consistently above 126 mg/dL, you very likely have diabetes.

There are several tests that can detect the presence of diabetes.

1) Fasting Blood Glucose test

Because blood glucose levels rise after eating, overnight fasting (or fasting for a period of 8 hours) prior to the test is preferred. This test is as simple as any blood test where blood is drawn from your arm and sent out to a lab for analysis, where the level of blood sugar in your blood is measured. If the level is too high, your doctor will likely repeat the test before concluding that you have diabetes.

2) Random blood sugar test

This test is done at the same time as your blood is tested for any other problems. It does not require fasting, and because the patient may have eaten prior to the test, levels under 200 mg/dL are not considered alarming, until a fasting blood glucose test is completed. This test should be done if the glucose level is above 126 mg/dL.

3) Finger prick blood sugar test

This test is fast and easy, only requiring a pin prick single drop of blood. This drop of blood is placed onto a strip that has been treated chemically, which is then inserted into a machine capable of measuring blood sugar levels. If your blood sugar level is above 126 mg/dL, more conclusive tests, such as a fasting blood glucose test, should be done.

4) Glycated hemoglobin test (hemoglobin A-1C test)

This test is usually carried out only after a diagnosis of diabetes has been made. This test allows your doctor to measure your blood glucose level over the previous 2 or 3 months. This test measures the amount of blood sugar attached to hemoglobin molecules. The body's hemoglobin molecules are iron rich molecules that are present in red blood cells and that deliver oxygen to the body. The more hemoglobin molecules with sugar attached that are present in your red blood cells, the higher the blood sugar levels.

5) Glucose tolerance test

After fasting for 8 hours, 8 ounces of sweet liquid is consumed. Blood sugar levels are tested prior to drinking the liquid, then every hour for 3 hours after. The amount that blood sugar levels rise in these hours can indicate the presence of diabetes. This test is often used to screen pregnant women for gestational diabetes.

Read more from the National Institute of Diabetes. For Americans living with diabetes, the American Diabetes Association offers useful information, resources and support.

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