What Is Prediabetes?

Prediabetes is a wake-up call that you’re on the path to diabetes. But it’s not too late to turn things around.

If you have it (like 86 million other Americans), your blood sugar (glucose) level is higher than it should be, but not in the diabetes range. People used to call it "borderline" diabetes.

Normally, your body makes a hormone called insulin to help control your blood sugar. When you have prediabetes, that system doesn't work as well as it should. You might not be able to make enough insulin after eating, or your body might not respond to insulin properly.

Prediabetes makes you more likely to get heart disease or have a stroke. But you can take action to lower those risks.


Your doctor will give you one of three simple blood tests:

Fasting plasma glucose test. You won't eat for 8 hours before taking this blood test. The results are:

  • Normal if your blood sugar is less than 100
  • Prediabetes if your blood sugar is 100-125
  • Diabetes if your blood sugar is 126 or higher

Oral glucose tolerance test. First, you'll take the fasting glucose test. Then you'll drink a sugary solution. Two hours after that, you'll take another blood test. The results are:

  • Normal if your blood sugar is less than 140 after the second test
  • Prediabetes if your blood sugar is 140-199 after the second test
  • Diabetes if your blood sugar is 200 or higher after the second test

Hemoglobin A1C (or average blood sugar) test. This blood test shows your average blood sugar level for the past 2 to 3 months. Doctors can use it to diagnose prediabetes or diabetes or, if you already know you have diabetes, it helps show whether it's under control. The results are:

  • Normal: 5.6% or less
  • Prediabetes: 5.7 to 6.4%
  • Diabetes: 6.5% or above

You may need to take the test again to confirm the results.

3 Key Lifestyle Changes to Make Now

Lifestyle changes can help many people with prediabetes delay or prevent it from becoming diabetes.

In a large research study called the Diabetes Prevention Program, these changes cut the odds of getting diabetes:

1. Weight control. If you're overweight, your prediabetes is more likely to turn into diabetes. Losing even as little as 5% to 10% of your body weight makes a difference.

2. Exercise. Get moderate exercise for 30 minutes a day, such as cycling, swimming, or brisk walking. It helps prevent and manage diabetes, studies show. Aerobic exercise, the kind that gets your heart rate up, is ideal. If you're not active now, check with your doctor first.

3. Nutrition. Go for meals that mix low-fat protein, vegetables, and whole grains. Limit calories, serving sizes, sugar, and starchy carbs. Favor fiber-rich foods, which help you feel full and not eat too much.

WebMD Medical Reference Reviewed by Michael Dansinger, MD on November 01, 2018



American Diabetes Association: "Prediabetes;" "How to Prevent Prediabetes;" "How to Tell if You Have Prediabetes;" and "Diabetes Mellitus and Exercise: Position Statement."

National Diabetes Education Project: "About Diabetes and Prediabetes."

National Library of Medicine: "Diabetes."

National Diabetes Information Clearinghouse (NDIC): "Prediabetes: Impaired Glucose Tolerance and Impaired Fasting Glucose" and "Prevention or Delay of Diabetes."

MedicineNet.com: "Diabetes: Preventing Type 2 Diabetes."

Labtestsonline.org: "Diabetes."

CDC: "Diabetes Latest."

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