Trusted medical advice from the American Academy of Family Physicians

Prediabetes Overview 

What is prediabetes? 

 
Prediabetes means your blood glucose (also called blood sugar) levels are higher than normal. When your blood glucose levels reach a certain level, you have diabetes. This is a disease that occurs when your body doesn’t make or use the hormone insulin properly. It causes too much glucose to build up in the blood. Too much glucose in your blood can be harmful to your body over time. 

Prediabetes is when your blood glucose levels are too high, but not high enough to be called diabetes. People who develop type 2 diabetes usually have prediabetes first. If you have prediabetes, you are at much higher risk of developing type 2 diabetes. You are also at risk of developing other health conditions, including heart disease or stroke. 

The good news is that, if you have prediabetes, you can prevent or delay the onset of full-blown type 2 diabetes by making lifestyle changes. These include eating a healthy diet, reaching and maintaining a healthy weight, and exercising regularly. 

Symptoms of Prediabetes 

 
Prediabetes usually doesn’t cause any symptoms. The only way to know you have it is if your blood sugar levels are tested. 

Causes 
What causes prediabetes? 

 
Prediabetes happens when the insulin in your body doesn’t work as well as it should. Insulin helps the cells in your body use glucose from your blood. When the insulin doesn’t work properly, too much glucose builds up in your blood. Higher levels than normal can indicate prediabetes. If the levels get high enough, you develop type 2 diabetes. High glucose levels can damage your blood vessels and nerves. This increases your risk of heart disease, stroke, and other health problems. 

You are at risk for prediabetes if any of the following are true: 

You are overweight or obese. 
You have a parent, brother, or sister who has diabetes. 
You had diabetes during pregnancy (called gestational diabetes) or had a baby who weighed more than 9 pounds at birth. 
You are African American, Native American, Latin American or Asian/Pacific Islander. 
You have high blood pressure (above 140/90 mm Hg). 
Your HDL cholesterol level (“good” cholesterol) is too low (less than 40 mg per dL for men or 50 mg per dL for women), or your triglyceride level is higher than 250 mg per dL. 
You are a woman who has polycystic ovary syndrome (PCOS). 

 
Diagnosis 
How is prediabetes diagnosed? 

 
Your doctor can give you a blood test to check for prediabetes. He or she may want to test your “fasting blood sugar” first. Fasting blood sugar is your blood sugar level before you eat in the morning. The ranges for the results of a fasting blood sugar test are: 

Normal = between 70 and 99 mg per dL 
Prediabetes = between 100 and 125 mg per dL 
Diabetes = higher than 126 mg per dL. 

 
If your fasting blood test shows that you have prediabetes, your doctor may want to do an A1C blood test. Or, your doctor may skip the fasting blood sugar test and go straight to the A1C blood test. This test provides information about your average blood sugar levels over the past 3 months. The results are reported as a percentage: 

Normal = below 5.7% 
Prediabetes = between 5.7% and 6.4% 
Diabetes = 6.5% or higher. 

 
You should be tested for diabetes if you are age 45 or older. You should also be tested if you are younger than 45 and have any of the risk factors listed above. 

Can prediabetes be prevented or avoided? 
Prediabetes and type 2 diabetes can be delayed and even prevented. Usually this is done by losing weight if you are overweight, eating a healthy diet, and exercising regularly. The longer you have prediabetes or diabetes, the more health problems you may experience. So even just delaying the onset of the disease can help your health. 

If I have prediabetes, can I avoid developing diabetes? 
If you have prediabetes, the best way to avoid developing type 2 diabetes is by making changes in your lifestyle. 

Lose weight. If you are overweight, losing just 7 percent of your starting weight can help delay or prevent diabetes. That means if you weigh 200 pounds, losing 14 pounds can make a difference. Weight loss also helps lower your blood pressure and cholesterol levels. 

Exercise Regularly 

Exercise is an important part of diabetes prevention. Your exercise routine should include 30 minutes of moderate physical activity at least 5 times a week. This could include brisk walking, riding a bike, or swimming. Ask your doctor what exercise level is safe for you. 

 
Follow a healthy diet. 

Eat foods such as vegetables, fruits, whole grains, lean proteins such as fish or chicken, and low-fat dairy. Don’t eat a lot of processed, fried, or sugary foods. Eat smaller portions to reduce the number of calories you take in each day. Drink water instead of sweetened drinks. Your doctor might refer you to a dietitian or diabetes educator to help you change your eating and exercise habits. 

Some people take medicine to help prevent or delay diabetes. Ask your doctor if this is a good option for you. 

Prediabetes treatment 

 
The primary treatment for prediabetes is the same as what you do to prevent diabetes: lose weight, exercise, and eat a healthy diet. These 3 things can help control your blood sugar levels and keep them from getting higher. In some cases, your blood sugar levels might decrease. It is possible to reverse prediabetes by making these lifestyle changes. 

Can medicine help treat prediabetes? 
Diabetes medicines are not as effective as diet and exercise. However, your doctor might prescribe medicine if you are at high risk for diabetes and have other medical problems. These could include obesity, a high triglyceride level, a low HDL cholesterol level, or high blood pressure. 

Living with prediabetes 

 
When you’re living with prediabetes, you should focus on preventing full-blown diabetes. The best ways to do this are by losing weight, eating right, and exercising regularly. But these lifestyle changes can be hard. Here are some tips to help you make changes successfully. 

Take small steps 

 
Changing to a healthy lifestyle takes time and effort. But you don’t have to make all the changes at once. Start small, such as switching from drinking soda to drinking water. Once you’ve made the change, celebrate your progress. Then move on to the next change you need to make. It may take a while, but keep moving forward. Your lifestyle will continue to improve, and so will your health. 

Don’t let setbacks derail you. 
Nobody is perfect. It can be easy to slide back into old habits. If you slip up and have a setback, move back to your healthy habit as soon as you can. You might take one step backward sometimes, but as long as you keep moving forward, your health will improve. 

Find support 

 
It’s harder to do things by yourself. Find other people who are trying to make the same changes you are. They can provide encouragement and new ideas for you to try as you support each other. They also make you more accountable for your decisions. It’s a lot harder to skip a workout when you have someone who is waiting to do it with you. 

Educate yourself 

 
Learn about how to make healthier food decisions at the grocery store, in the kitchen, and when eating out. The more you know about how food works in your body and what you should be eating, the easier it is to make healthy choices for yourself. Your doctor may recommend nutritional counseling or a visit with a dietitian. They can help you break your old habits and learn how to live healthier. 

Remember the big picture 

 
The day-to-day decisions you need to make can be hard. But in the long run, they add up to make you a much healthier person. Prediabetes can be controlled and even reversed through hard work, focus, and good choices. You are changing your life, one step at a time. 

Questions to Ask Your Doctor 

 
1. If I have prediabetes, will I get diabetes? 
2. What is the best step I can take to avoid getting diabetes? 
3. My father has diabetes. Should I be screened for prediabetes on a regular basis? 
4. I have diabetes. Should I have my children screened for prediabetes? 
5. I had gestational diabetes. Should I be screened for prediabetes regularly? 
6. Are there any foods I should eat that will help me to avoid prediabetes? 
5. Should I speak with a dietitian about changing what I eat?