Prediabetes

Condition Basics

What is prediabetes?

Prediabetes is a warning sign that you are at risk for getting type 2 diabetes. It means that your blood sugar is higher than it should be. But it's not high enough to be diabetes.

The food you eat naturally turns into sugar. Your body uses the sugar for energy. Normally, an organ called the pancreas makes insulin. Insulin allows the sugar in your blood to get into your body's cells. But sometimes the body can't use insulin the right way. So the sugar stays in your blood instead. This is called insulin resistance. The buildup of sugar in your blood means you have prediabetes.

Prediabetes is also called impaired glucose tolerance or impaired fasting glucose. Most people who get type 2 diabetes have prediabetes first.

What causes it?

Prediabetes is caused by a buildup of sugar in your blood. Insulin allows sugar to get into your body's cells. When your body can't use insulin the right way, the sugar doesn't move into your body's cells. And that's how it builds up in your blood.

What are the symptoms?

Most of the time, people with prediabetes do not have symptoms.

How is it diagnosed?

Your doctor will ask questions about your medical history. You will also get a physical exam and blood glucose testing. The results help your doctor see if you have prediabetes and are at risk for type 2 diabetes.

How is prediabetes treated?

Prediabetes can be treated by making lifestyle changes, taking medicine, or doing both. Lifestyle changes include losing weight if you need to, keeping healthy eating habits, and getting active. Treatment may help get your blood sugar level back to a more normal range. It could help you prevent or delay type 2 diabetes.

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Cause

The food you eat turns into sugar, which your body uses for energy. Normally, an organ called the pancreas makes insulin, which allows the sugar in your blood to get into your body's cells. But when your body can't use insulin the right way, the sugar doesn't move into your cells. It stays in your blood instead. The buildup of sugar in your blood causes prediabetes.

What Increases Your Risk

You are more likely to get prediabetes if you:

  • Are overweight.
  • Get little or no exercise.
  • Have type 2 diabetes in your family.

Other things that may increase your risk for prediabetes include:

Age.
The risk of getting prediabetes and type 2 diabetes increases with age.
Race and ethnicity.
African Americans, Hispanics, Native Americans, Asian Americans, and Pacific Islanders are at higher risk for type 2 diabetes.
History of gestational diabetes.
Women who have had gestational diabetes are at higher risk for developing type 2 diabetes later in life.

Other health problems can put you at risk for prediabetes and type 2 diabetes. These include:

  • Polycystic ovary syndrome (PCOS).
  • History of heart disease.
  • High blood pressure.
  • Low HDL cholesterol and high triglyceride level.
  • Conditions linked with insulin resistance.

Prevention

Your risk for prediabetes is higher if you're overweight and physically inactive. To help prevent prediabetes:

Watch your weight.

Try to lose 7% to 10% of your body weight. For example, if you weigh 200 pounds, aim to lose 14 to 20 pounds. The easiest way to lose weight is to cut calories and be more active.

Make healthy food choices.

It can be hard to make big changes in the way you eat. It's okay to start small. Limit calories, sweets, and unhealthy fats. Eat more fruits, vegetables, and fiber.

Be active.

When you're active, your body uses glucose. The more active you are, the more glucose your body uses for energy. This keeps the sugar from building up in your blood. Exercise can also improve insulin resistance. Walking is a great way to start.

If you already have prediabetes, these same steps can keep it from turning into type 2 diabetes.

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What Happens

Prediabetes can lead to type 2 diabetes. If you get type 2 diabetes, you may have to carefully watch what you eat, take medicine every day, and watch for other health problems.

But not everyone with prediabetes will get type 2 diabetes. Major lifestyle changes can help prevent diabetes in people who have prediabetes. These changes include losing weight, eating healthier foods, and getting more exercise.

The medicine metformin can also help prevent type 2 diabetes in people who have prediabetes. But even if you take metformin, it's important to make as many healthy changes as you can. Doing both of these things may give you the best chance of delaying or preventing type 2 diabetes over the long term.

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When to Call a Doctor

When you have prediabetes, it's important to watch for symptoms of type 2 diabetes. Call your doctor if you notice that you are:

  • Feeling very thirsty a lot of the time.
  • Urinating more often than usual.
  • Feeling very hungry a lot of the time.
  • Having blurred vision.
  • Losing weight without trying.

You may want to talk to your doctor about testing for prediabetes if you are:

  • Interested in reducing your risk for getting type 2 diabetes.
  • Overweight.
  • Not able to exercise regularly.

Exams and Tests

Your doctor will ask questions about your medical history. You will also get a physical exam and blood sugar (glucose) testing. The results help your doctor see if you have prediabetes and are at risk for getting type 2 diabetes.

Blood tests used to diagnose prediabetes in adults include:

Fasting blood glucose test.
This test is usually done after you fast overnight for 8 hours.
Hemoglobin A1c.
This test estimates your blood sugar over the past 2 to 3 months.
Oral glucose tolerance test (OGTT).
For an OGTT, your blood sugar is measured after fasting. Then it's tested again 2 hours after you drink a special glucose liquid.

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Treatment Overview

When you have prediabetes, you have a chance to prevent or delay type 2 diabetes. Treatment focuses on:

Watching your weight.
A healthy weight helps your body use insulin the way it should. If you're overweight, losing weight can also lower your body's resistance to insulin.
Making healthy food choices.
Limit the amount of saturated fat and trans fat you eat. Cut calories and limit sweets.
Getting active.
Exercise keeps sugar from building up in your blood. It can also improve insulin resistance.
Quitting smoking, if you smoke.
Medicines and counseling can help.
Preventing or managing high blood pressure and high cholesterol.
Medicines can help lower blood pressure and cholesterol.

Doing these things will also help you avoid other health problems, like heart disease and stroke, that are linked to diabetes.

You may need to take medicine called metformin. It reduces the amount of sugar made by the liver in people who are insulin-resistant.

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Setting a Goal to Prevent Type 2 Diabetes

Losing weight, getting active, and eating better are the best things you can do to prevent or manage type 2 diabetes. The following steps can help you set a goal to make a change for your health.

  1. Know your reason for wanting to change.

    Before you set a goal, think about why you want to make a change. Your reason for wanting to change is important. If your reason comes from you—and not from someone else—it will be easier for you to make a healthy change for good. For example:

    • Maybe you want to avoid the hassles that come with type 2 diabetes, such as taking insulin or testing blood sugar.
    • Maybe you're worried about the health problems that diabetes brings.
    • You might simply want to enjoy your life and have more energy.
  2. Set long-term and short-term goals.

    Start by setting a big, or long-term, goal. Maybe you want to lose 10% of your body weight. If you weigh 200 lb (91 kg), that means losing 20 lb (9 kg).

    Break down your big goal into smaller, short-term goals. These are the steps you'll take to reach your big goal. Do what works best for you. It's important to set goals you can reach. For example:

    • Week 1: Set a goal to walk for 15 minutes, 5 days a week.
    • Week 2: Continue to walk for 15 minutes, 5 days a week. And this week, when you reach for a snack, make it carrots or celery sticks instead of potato chips or crackers.
    • Week 3: Keep up your walking program and eating healthy snacks. Bit by bit, increase your walks to 30 minutes for at least 5 days each week. Pay attention to your hunger levels when you eat meals. Stop eating when you feel full.
  3. Prepare for slip-ups and barriers.

    Plan for setbacks. Use a personal action plan to write down your goals, any possible barriers to success, and your ideas for getting past them. By thinking about these barriers now, you can plan ahead for how to deal with them if they happen.

Tips for staying on track:

  • Get support. Tell family and friends your reasons for wanting to change. Tell them that their encouragement makes a big difference to you in your goal to prevent type 2 diabetes. Your doctor or a professional counselor can also provide support.
  • Pat yourself on the back. Don't forget to give yourself some positive feedback. If you slip up, don't waste energy feeling bad about yourself. Instead, think about how much closer you are to reaching your goal than when you started.

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Self-Care

You can make healthy changes to help prevent or delay type 2 diabetes.

  • Limit the amount of calories, sweets, and unhealthy fat you eat.
  • Lose weight if you need to. Even losing a small amount of weight can help.
  • Try to exercise at least 2½ hours a week. Bit by bit, increase the amount you do every day.

When you have prediabetes, you're also at higher risk for heart disease and stroke. You can lower your risk by:

  • Managing other health problems, such as high blood pressure and high cholesterol. Exercise, healthy eating, and/or medicine can help with these goals.
  • Quitting smoking. Quitting smoking might help you reduce your risk for type 2 diabetes and heart disease and help you avoid other health problems that make diabetes worse.

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Credits

Current as of: March 1, 2023

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
David C.W. Lau MD, PhD, FRCPC - Endocrinology