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Am Fam Physician. 2004;69(8):1971-1972

What is type 2 diabetes? What is prediabetes?

Diabetes is a disease in which blood sugar levels are higher than normal. High blood sugar can cause heart attack, stroke, kidney disease, nerve damage, and vision loss. Type 2 diabetes is the most common form of diabetes.

Before people get type 2 diabetes, they usually go through a prediabetic stage. Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are the two kinds of prediabetes. In people with IGT and IFG, blood sugar levels are higher than normal but not high enough to say they have diabetes. People with prediabetes have a high risk of getting diabetes. They also are more likely to have a heart attack.

How can my doctor tell if I have prediabetes or diabetes?

Your doctor can use a blood test to see if you have diabetes or prediabetes.

Who is at risk for getting prediabetes and diabetes?

You are at risk for getting prediabetes or diabetes if:

  • You are overweight or obese.

  • You have a parent, brother, or sister with diabetes.

  • You were diagnosed with diabetes during pregnancy or had a baby that weighed more than 9 pounds at birth.

  • You belong to any of the following ethnic groups: black, Native American, Latin American, or Asian/Pacific Islander.

  • You have high blood pressure (above 140/90 mm Hg).

  • Your high-density lipoprotein (HDL) cholesterol level (good cholesterol) is less than 40 mg per dL (for men) or less than 50 mg per dl (for women), or your triglyceride level is higher than 250 mg per dL.

What can I do to prevent diabetes?

By making changes in your lifestyle, you can lower your risk of getting diabetes. If you are overweight, losing 5 to 7 percent of your total body weight can help. Losing weight also will lower your blood pressure and cholesterol levels.

Exercise of any kind can lower your risk of getting diabetes. Your exercise routine should include 30 minutes of moderate physical activity at least five times a week. Be sure to stay at an exercise level that your doctor says is safe for you.

Following a healthy diet also can help. Eat foods like salads, vegetables, fruits, whole grains, fish, beans, poultry, and other meats. Don't eat a lot of white sugar, honey, or molasses. Eat foods made with whole grains instead of white flour.

Less than 30 percent of your total daily calories should come from fat. Less than 10 percent of your daily calories should come from saturated fat. Carbohydrates should make up 50 to 60 percent of your total daily calories. Your diet also should include at least 20 grams of fiber per day.

Your doctor might refer you to a dietitian or diabetic educator for help in changing your eating habits.

Can diabetes medicines help prevent or delay diabetes?

Diabetes medicines are not as effective as diet and exercise. Your doctor might prescribe a diabetes medicine if you are at high risk for diabetes and have other medical problems, such as obesity, a high triglyceride level, a low HDL cholesterol level, or high blood pressure.

Where can I get more information?

  • American Diabetes Association

  • ATTN: National Call Center

  • 1701 North Beauregard Street

  • Alexandria, VA 22311

  • Web site address:

  • Telephone: 1–800–DIABETES (1–800–342–2383)

  • National Diabetes Information Clearinghouse

  • 1 Information Way

  • Bethesda, MD 20892–3560

  • Web site address:

  • Telephone: 1–800–860–8747

  • National Diabetes Education Program

  • Office of Communications and Public Liaison

  • NIDDK, NIH, Building 31, Room 9A04 Center Drive, MSC 2560

  • Bethesda, MD 20892–3560

  • Web site address:

  • CDC Diabetes Public Health Resource

  • CDC Division of Diabetes Translation

  • PO. Box 8728

  • Silver Spring, MD 20910

  • Web site address:

  • Telephone: Toll free 1–877–CDC-DIAB (877–232–3422)

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