Topic Overview

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 not high enough to be diabetes. Prediabetes is also called impaired glucose tolerance or impaired fasting glucose. Most people who get type 2 diabetes have prediabetes first.

What causes prediabetes?

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 cells. It stays in your blood instead. This is called insulin resistance. The buildup of sugar in the blood causes prediabetes.

People who are overweight, aren’t physically active, and have a family history of diabetes are more likely to get prediabetes. Women who have had gestational diabetes are also more likely to get prediabetes.

What are the symptoms?

Most people with prediabetes don’t have any symptoms. But if you have prediabetes, you need to watch for signs of diabetes, such as:

• Feeling very thirsty.
• Urinating more often than usual.
• Feeling very hungry.
• Having blurred vision.
• Losing weight without trying.

How is prediabetes diagnosed?

A blood test can tell if you have prediabetes. You have prediabetes if:

• The results of your hemoglobin A1c test are 5.7% to 6.4%.
• The results of your fasting blood glucose test are between 100 and 125 milligrams per deciliter.
• The results of your oral glucose tolerance test (OGTT) are 140 to 199 mg/dL (2 hours after the beginning of the test).

How is it treated?

The key to treating prediabetes and preventing type 2 diabetes is getting your blood sugar levels back to a normal range. You can do this by making some lifestyle changes.

• Watch your weight. If you are overweight, losing just a small amount of weight may help. Reducing fat around your waist is particularly important.
• Make healthy food choices. Limit the amount of unhealthy fat you eat, such as saturated fat and trans fat. Try to cut calories and limit sweets.
• Be active. You can do moderate activity, vigorous activity, or both. Bit by bit, increase the amount you do every day. You may want to swim, bike, or do other activities. Walking is an easy way to get exercise.

Making these changes may help delay or prevent diabetes. You may also avoid or delay some of the serious problems that you can get when you have diabetes, such as heart attack, stroke, and heart, eye, nerve, and kidney disease.

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

Can prediabetes be prevented?

Staying at a healthy weight, eating healthy foods, and getting regular exercise can help prevent prediabetes.

Cause

Prediabetes occurs when your body isn’t able to keep your sugar (glucose) at a normal level in your blood. Your blood sugar is higher than normal, but it’s not high enough to be diabetes.

The food you eat turns into sugar, which your body uses for energy. Normally, the pancreas makes insulin, which allows the sugar in blood to get into the body’s cells. But when your body can’t use insulin the right way, the sugar doesn’t move into cells. It stays in your blood instead. This is called insulin resistance.

The buildup of sugar in the blood causes prediabetes. If your blood sugar stays too high for too long, prediabetes can turn into type 2 diabetes.

People who are overweight, aren’t physically active, and have a family history of diabetes are more likely to get prediabetes. Women who have had gestational diabetes are also more likely to get prediabetes.

Symptoms

Most of the time, prediabetes has no symptoms. But if you have prediabetes, you need to watch for signs of type 2 diabetes, such as:

• Feeling very thirsty.
• Urinating more often than usual.
• Feeling very hungry.
• Having blurred vision.
• Losing weight without trying.

What Happens

Prediabetes is a warning sign that you are at risk for getting type 2 diabetes.

When you have prediabetes, you’re also at higher risk for eye, nerve, kidney and heart disease, and for stroke. For more information on these complications, see the topic Type 2 Diabetes.

One Man’s Story: Jerry, 54 When he first found out he had prediabetes, Jerry felt angry and frustrated. His doctor told him to lose weight and get more exercise, or else run the risk of getting type 2 diabetes. “I thought, ‘What’s the point? I might still get diabetes.’ I felt like I was stuck either way. But it turns out there’s a lot you can do.”— Jerry Read more about Jerry.

You can reduce your risk for type 2 diabetes and related health problems by making healthy lifestyle changes, such as:

• Watching your weight.
• Making healthy food choices.
• Being active.

For more information, see Prevention.

What Increases Your Risk

Risk factors

Things that can increase your chances of prediabetes are called risk factors. Some risk factors you can control, and others you can’t.

The risk factors for prediabetes are similar to those for type 2 diabetes. Most people who get type 2 diabetes had prediabetes first. Risk factors include:

• Being overweight.
• Lack of physical activity.
• Family history. If you have a parent, brother, or sister who has type 2 diabetes, you have a greater chance of getting the disease.
• Age. The risk for getting prediabetes and type 2 diabetes increases with age. But the number of children with type 2 diabetes is increasing. Usually, children who get type 2 diabetes have a family history of the disease, are overweight, and aren’t physically active.
• Race and ethnicity. African Americans, Hispanics, Native Americans, Asian Americans, and Pacific Islanders are at higher risk than whites for type 2 diabetes.
• History ofgestational diabetes. Women who have had gestational diabetes are at higher risk for type 2 diabetes later in life.

Other health problems that put you at risk for prediabetes and type 2 diabetes include:

• Polycystic ovary syndrome (PCOS). PCOS is a problem in which a woman’s hormones are out of balance.
• A history of heart disease.
• High blood pressure.
• Your high-density lipoprotein (HDL) cholesterol is low and/or your triglyceride level is high.
• A skin condition called acanthosis nigricans, which is linked to insulin resistance.

One Woman’s Story: Linda, 39 With a family history of type 2 diabetes, Linda says she should have watched her weight more carefully. She wasn’t too surprised by her prediabetes diagnosis. But she got motivated right away to do what she could about it. “I watched my mom inject herself with insulin every day. Sometimes she needed my help. She had the hardest time keeping her blood sugar down and figuring out what to eat. I don’t want to go down that road if I can help it.”— Linda Read more about Linda.

Reducing your risk

There are some things you can do to reduce your chances of getting prediabetes:

• Watch your weight. Being overweight increases your risk for prediabetes and type 2 diabetes. Your risk also increases if most of your body fat is in your belly area. Losing even 7 percent of your body weight can reduce your risk.
• Make healthy food choices. Eating healthy food is one of the best things you can do for your health.
• Be active. The less you exercise, the greater your risk of getting prediabetes and type 2 diabetes. The more active you are, the more sugar (glucose) your body uses for energy. This keeps the sugar from building up in your blood.

When you have prediabetes, it’s important to follow your treatment. This can reduce your risk of prediabetes turning into type 2 diabetes.

For more tips about things you can do to reduce your risk, see Prevention.

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:

• Overweight and get little or no exercise.
• Interested in reducing your risk for getting type 2 diabetes.

Exams and Tests

What tests will you have for prediabetes?

Your doctor will do a medical history, a physical exam, and blood glucose testing to find out if you have prediabetes and are at risk for getting type 2 diabetes.

Blood tests used to identify 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 and then again 2 hours after you drink a special glucose liquid. This test is not done as often as the fasting glucose test, which is more convenient.

You have prediabetes if:

• The results of your A1c test are 5.7% to 6.4%. For all of these tests, lower numbers are best.
• The results of your fasting blood glucose test are 100 to 125 milligrams per deciliter (mg/dL).
• The results of your OGTT are 140 to 199 mg/dL (2 hours after the beginning of the test).

Phrases such as “a touch of diabetes,” “borderline diabetes,” and “your sugar is a little high” are unclear. If you hear these phrases, ask your doctor if your blood sugar level is in the prediabetes or diabetes range.

Tests for other health problems

If you are diagnosed with prediabetes, your doctor may also want to:

• Check your blood pressure.
• Do a blood test to check your cholesterol levels.
• Test your blood sugar regularly to check for type 2 diabetes.

Treatment Overview

Your treatment for prediabetes will focus on losing weight, eating healthy foods, and getting active. This is your chance to reverse prediabetes so it doesn’t turn into type 2 diabetes. Doing these things will also help you avoid other health problems, such as heart disease and stroke, that are linked to diabetes.

You may also need to take diabetes medicine along with doing these things.

• Prediabetes: Which Treatment Should I Use to Prevent Type 2 Diabetes?

Watch your weight

Most people who have prediabetes are overweight and have a body mass index (BMI) of 25 or higher. To find out your BMI, use the Interactive Tool: Is Your BMI Increasing Your Health Risks?

If you have a BMI of 25 or higher, try to lose 7% to 10% of your body weight. For example, if you weigh 200 pounds, aim to lose 14 to 20 pounds.

A healthy weight helps your body use insulin the way it should. Losing weight can also lower insulin resistance in people who have prediabetes. The more you lose, the more you benefit, as long as you do it in a healthy way.

How you do it is up to you. One way to start is by making healthy eating changes that you can keep doing over time. Try reducing the number of calories you eat and drink and adding more activity to your day. For help, see the topic Weight Management.

One Man’s Story: Jerry, 54 Jerry signed up for a weight-loss program and started a daily food diary to track what and when he ate. He added walks around the neighborhood and visits to the gym to his routine. In 7 months, he dropped 25 pounds—about 10% of his body weight. “It hasn’t been easy. I’ve had some ups and downs, especially over the holidays. Hey, I love to eat. Sometimes it’s hard to stay focused. But tracking what, when, and why I eat helps me to eat less.”— Jerry Read more about Jerry.

Make healthy food choices

Eating a balanced diet is one of the best things you can do for yourself and for your health. Try to:

• Limit the amount of unhealthy fat you eat, such as saturated fat and trans fat.
• Cut calories.
• Limit sweets.

Get active

The more active you are, the more sugar (glucose) your body uses for energy. This keeps the sugar from building up in your blood. Exercise can also improve insulin resistance.

Try to do moderate activity at least 2½ hours a week. Or try to do vigorous activity at least 1¼ hours a week. It’s fine to be active in blocks of 10 minutes or more throughout your day and week.

Moderate activity is safe for most people, but it’s always a good idea to talk to your doctor before you start an exercise program. For more help, see the topic Fitness.

One Woman’s Story: Linda, 39 Linda works full-time, has three young children, and has zero time for the gym. So when she learned she had prediabetes, she had to find creative ways to fit activity into her day. For example, after dinner she turns up the stereo and does dance moves while washing dishes, putting food away, and cleaning the kitchen. “It takes about a half-hour and is a great workout. My kids get a big kick out of it too.”— Linda Read more about Linda.

Take medicine if you need to

You may need to take an oral medicine, such as metformin. It reduces the amount of sugar made by the liver in people who are insulin resistant.

If you do need medicine, be sure to take it as directed.

If you smoke, quit

Quitting smoking might help you reduce your risk for type 2 diabetes and heart disease and also might help you avoid other health problems that make diabetes worse. Quitting can also reduce your risk of heart attack and stroke. For more information, see the topic Quitting Smoking.

Prevent heart disease

When you have prediabetes, you are more likely to get heart disease than someone who has normal blood sugar levels. Your risk of having heart disease is even higher if you have high blood pressure or high cholesterol. That is why it’s important to have a heart-healthy lifestyle. This includes preventing or managing high blood pressure and high cholesterol.

Prevention

Even if you have risk factors for prediabetes, you can still take steps to prevent the disease. And if you already have prediabetes, these same steps can keep it from turning into type 2 diabetes.

Your risk for prediabetes is higher if you are overweight and physically inactive. So:

• 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. Losing weight can be hard, but you can do it. The easiest way to start is by cutting calories and getting more active. For help, see the topic Weight Management.
• Make healthy food choices.It can be hard to make big changes in the way you eat. It’s okay to start small, by limiting the amount of calories, sweets, and unhealthy fat you eat and by eating more fruits, vegetables, and fiber. For help, see the topic Healthy Eating.
  • Healthy Eating: Cutting Unhealthy Fats From Your Diet
  • Healthy Eating: Changing Your Eating Habits
• 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. For help, see the topic Fitness.
  • Quick Tips: Getting Active At Home
  • Fitness: Adding More Activity to Your Life

Setting a Goal to Prevent Type 2 Diabetes

Prediabetes is a warning sign that you are at risk for type 2 diabetes. But you can make the healthy changes needed to prevent it.

Losing weight, getting active, and eating better are all important changes you can make for your health. These are the best things you can do to prevent prediabetes or to stop it from turning into type 2 diabetes. Three steps can help you get started.

1. Know your reason. Before you set a goal, think about why you want to make a change. If your reason comes from you—and not from someone else—it will be easier for you to make a healthy change for good.

Maybe you want to avoid the hassles that come with type 2 diabetes, such as taking insulin or testing blood sugar. Or maybe you are worried about the health problems diabetes brings. You might simply want to enjoy your life and have more energy. Your reason for wanting to change is important.

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 to reduce your risk of type 2 diabetes. If you weigh 200 pounds, that means losing 20 pounds. 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. Gradually increase walking 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( What is a PDF document? ) to write down your goals, any possible barriers, 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.

Medications

Your doctor may prescribe metformin (Glucophage). If you need medicine, your doctor is most likely to prescribe this one. Metformin reduces how much glucose the liver makes. It can also lower insulin resistance.

Talk with your doctor to find out if you need medicine in addition to lifestyle changes to lower your insulin resistance.