Testing for Diabetes - What to Expect

Your doctor will discuss with you:

• Family history of diabetes;
• Your personal health assessment - record your height and weight, discuss your risk factors for developing diabetes;
• Any signs of diabetes that you may be experiencing.

Based on this assessment your doctor may decide to go ahead with blood glucose tests that will determine whether or not you have diabetes.

In a person without diabetes, blood sugar levels don't vary that much over the course of the day. In diabetics, however, blood sugar can "spike". The diabetes tests will tell your doctor whether your blood sugar levels are normal; whether you are considered pre-diabetic; or whether you have diabetes.

Fasting Blood Sugar

The most common test is the fasting blood sugar test. For this test, you will have to stop eating for 8 to 12 hours prior to the test. A sample of blood is drawn and the amount of glucose is measured.

Normal range: 70 mg/dl to 100 mg/dl (milligrams/decilitre).
Pre-diabetic range: 101 mg/dl to 125 mg/dl.
Diabetic range: Above 125 mg/dl.

Random Blood Sugar

The random blood sugar test (also called a casual blood glucose test) is another way to test for diabetes. In this test your blood glucose is measured at any time of the day, and does not depend on when you eat or drink. Several measurements may be taken throughout the day.

Normal range: although a definitive level hasn't been established, someone without diabetes who has just eaten shouldn't have blood sugar levels above 200 mg/dl, and typically less than 180 mg/dl.

Pre-diabetic range: 140 mg/dl to 199 mg/dl may indicate pre-diabetes

Diabetic range: 200 mg/dl or above may indicate diabetes

Oral Glucose Tolerance Test

Finally, there is the oral glucose tolerance test. Once again you will need to fast for 8 hours minimum. Your blood sugar is then measured. Next, you're given a sugary drink and your blood sugar is again measured one and two hours after you've consumed the drink.

Normal range: less than 140 mg/dl.
Pre-diabetic range: 140 mg/dl to 199 mg/dl.
Diabetic range: 200 mg/dl or above, two hours after you drink.

Many people go for years without knowing that they have type 2 diabetes. Testing for diabetes is the only way to know for sure. If your blood tests indicate that you are pre-diabetic or diabetic, your doctor will repeat the tests and/or order additional tests in order to confirm the diagnosis.