Prediabetes

Date Updated: 09/10/2026

Overview

Prediabetes means having a higher than typical blood sugar level. It's not high enough to be type 2 diabetes yet. But without lifestyle changes, adults and children with prediabetes are at high risk of getting type 2 diabetes.

People with prediabetes may have some of the long-term damage to the heart, blood vessels and kidneys that diabetes causes. But the risk gets much higher if they get type 2 diabetes. There are ways to keep prediabetes from becoming type 2 diabetes.

Eating healthy foods, being physically active and staying at a healthy weight can help bring your blood sugar level back down. The same lifestyle changes that can help prevent type 2 diabetes in adults also may help children.

Symptoms

Prediabetes often has no clear symptoms.

One possible sign of prediabetes is darkened skin on certain parts of the body. Affected areas can include the neck, armpits and groin. Darkened skin may look dark brown or black on brown or Black skin and light brown or tan on white skin.

Symptoms that may mean you've moved from prediabetes to type 2 diabetes include:

Greater thirst.
Urinating more often.
Greater hunger.
Tiredness.
Blurred vision.
Numbness or tingling in the feet or hands.
Repeat infections.
Slow-healing sores.
Weight loss without trying.

When to see a doctor

See your healthcare professional if you're worried about diabetes or if you have any type 2 diabetes symptoms. Ask your healthcare professional about blood sugar screening if you have risk factors for diabetes.

Causes

Experts don't know the exact cause of prediabetes. But family history and genes seem important. What is clear is that people with prediabetes have trouble managing blood sugar, also called glucose.

Most of the glucose in your body comes from the food you eat. When you digest food, sugar enters your bloodstream. Insulin allows sugar to enter your cells and lowers the amount of sugar in your blood.

A gland that sits behind the stomach called the pancreas makes insulin. Your pancreas sends insulin to your blood when you eat. When your blood sugar level starts to drop, the pancreas slows down the amount of insulin that goes into the blood.

When you have prediabetes, this process doesn't work as well. As a result, instead of fueling your cells, sugar builds up in your bloodstream. This can happen because:

Your pancreas doesn't make enough insulin.
Your cells resist the insulin and don't let in as much sugar. This is called insulin resistance.

Risk factors

The same factors that raise the risk of getting type 2 diabetes also raise the risk of prediabetes. These factors include:

Weight. Being overweight is a main risk factor for prediabetes. The more fatty tissue your body has, the more your cells resist insulin. This is mainly true for fatty tissue inside and between the muscle and skin around your belly.
Waist size. A large waist may mean insulin resistance. The risk of insulin resistance goes up for people assigned male at birth with waists larger than 40 inches and for people assigned female at birth with waists larger than 35 inches.
Diet. Diets high in red meats, processed foods, saturated fat and sugar are linked with a higher risk of prediabetes.
Not being active. The less active you are, the higher your risk of prediabetes.
Age. Although diabetes can happen at any age, the risk of prediabetes goes up after age 35.
Family history. Your risk of prediabetes rises if you have a parent or sibling with type 2 diabetes.
Race or ethnicity. It's not clear why, but certain people are more likely to get prediabetes. In the United States, these include Black, Hispanic, American Indian and Asian American people.
Gestational diabetes. If you had diabetes while pregnant, also called gestational diabetes, you and your child are at higher risk of getting prediabetes. Low birth weight babies also have a higher risk.
Polycystic ovary syndrome. This condition involves having menstrual periods that aren't regular, excess hair growth and obesity. It raises the risk of prediabetes.
Sleep. People with obstructive sleep apnea are at higher risk of insulin resistance. Obstructive sleep apnea is a condition that disrupts sleep throughout the night. People who are overweight or people with obesity have a higher risk of getting obstructive sleep apnea.
Tobacco smoke. Smoking may raise insulin resistance and the risk of type 2 diabetes in people with prediabetes. Smoking also raises the risk of complications from diabetes.

Other conditions linked with a higher risk of prediabetes include:

High blood pressure.
Low levels of high-density lipoprotein (HDL) cholesterol, the "good" cholesterol.
High levels of triglycerides, a type of fat in the blood.

Metabolic syndrome

If you have certain conditions with obesity, you may have a higher risk of diabetes, heart disease and stroke. If you have three or more of these conditions, it's often called metabolic syndrome:

High blood pressure.
Low levels of high-density lipoprotein (HDL) cholesterol, the "good" cholesterol.
High levels of triglycerides, a type of fat in the blood.
High blood sugar levels.
Large waist size.

Complications

Prediabetes has been linked with long-term damage, including to your heart, blood vessels and kidneys. This is true even before you get type 2 diabetes. Prediabetes also is linked to what's called silent heart attacks. Silent heart attacks have few symptoms or have symptoms that aren't like those of a heart attack.

Prediabetes can go on to be type 2 diabetes, which can lead to:

High blood pressure.
High cholesterol.
Heart issues.
Stroke.
Kidney issues.
Nerve damage.
Fatty liver disease.
Eye damage, including loss of vision.
Surgery to remove a part of the body, called an amputation.

Prevention

Healthy lifestyle choices can help you prevent prediabetes and its move to type 2 diabetes, even if diabetes runs in your family. These include:

Eating healthy foods.
Getting active.
Losing excess weight.
Managing your blood pressure and cholesterol.
Not smoking.

Diagnosis

The American Diabetes Association (ADA) suggests diabetes screening for most adults starting at age 35. The ADA suggests diabetes screening before age 35 for those who have excess weight and other risk factors for prediabetes or type 2 diabetes. The same tests used to diagnose diabetes also diagnose prediabetes.

If you've had gestational diabetes, your healthcare professional is likely to check your blood sugar levels at least once every three years.

Blood tests for diabetes and prediabetes include:

Glycated hemoglobin (A1C) test

This test shows your average blood sugar level for the past 2 to 3 months.

In general:

Below 5.7% is healthy.
Between 5.7% and 6.4% is prediabetes.
6.5% or higher on the test done twice means diabetes.

Certain conditions can keep the A1C test from giving a true result. These include pregnancy and a form of hemoglobin that isn't common. Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the rest of the body.

Fasting blood sugar test

This uses a blood sample you give after not eating for at least eight hours.

Blood sugar values are given in milligrams of sugar per deciliter (mg/dL) or millimoles of sugar per liter (mmol/L) of blood. In general:

Less than 100 mg/dL (5.6 mmol/L) is healthy.
100 to 125 mg/dL (5.6 to 6.9 mmol/L) is prediabetes.
126 mg/dL (7.0 mmol/L) or higher on the test done twice is diabetes.

Oral glucose tolerance test

Healthcare professionals use this test less often than the others, except during pregnancy. You fast overnight and then go to a medical office or lab to drink a sugary liquid. A technician tests your blood sugar levels over the next two hours.

In general:

Less than 140 mg/dL (7.8 mmol/L) is healthy.
140 to 199 mg/dL (7.8 to 11.0 mmol/L) suggests prediabetes.
200 mg/dL (11.1 mmol/L) or higher after two hours suggests diabetes.

If you have prediabetes, your healthcare professional is likely to check your blood sugar levels at least once a year.

Children and prediabetes testing

Type 2 diabetes is becoming more common in children and adolescents. This is likely due to the rise in childhood obesity.

The ADA suggests prediabetes testing for children who are overweight or children with obesity and who have one or more other risk factors for type 2 diabetes, such as:

Family history of type 2 diabetes.
Being of a race or ethnicity linked with an increased risk.
Low birth weight.
Being born to a person who had gestational diabetes.

The ranges of blood sugar levels considered healthy, prediabetes and diabetes are the same for children and adults.

Healthcare professionals suggest testing children who have prediabetes for type 2 diabetes yearly. Children who have a change in weight or get symptoms of diabetes may have testing more often. Symptoms include greater thirst, urinating more, tiredness or blurred vision.

Treatment

Healthy lifestyle choices can help you bring your blood sugar level down or at least keep it from rising to type 2 diabetes levels.

To prevent prediabetes from getting to type 2 diabetes:

Eat healthy foods. A diet rich in fruits, vegetables, nuts and whole grains is linked with a lower risk of prediabetes. Choose foods low in fat and calories and high in fiber. Eat a variety of foods.
Be more active. Physical activity helps you manage your weight, uses up sugar for energy and helps the body use insulin better. Aim for at least 150 minutes of moderate or 75 minutes of vigorous aerobic activity a week. Or do both moderate and vigorous exercise.
Get to and stay at a healthy weight. If you are overweight, losing just 5% to 7% of your body weight can greatly lower the risk of type 2 diabetes. This means losing about 14 pounds (6.4 kilograms) for someone who weighs 200 pounds (91 kilograms). To stay at a healthy weight, make long-term changes to your eating and exercise habits.
Get good sleep. Getting 7 to 8 hours of restful sleep a night may lower the risk of prediabetes turning into type 2 diabetes.
Stop smoking. Stopping smoking can improve the way insulin works and improve your blood sugar level.
Take medicines as needed. If you're at high risk of diabetes, your healthcare professional might suggest metformin (Glumetza). You also might take medicines to manage cholesterol and high blood pressure.

Children and prediabetes treatment

Lifestyle changes for children with prediabetes are the same as for adults with type 2 diabetes, including:

Losing weight.
Eating fewer fats, fewer refined carbohydrates, such as white bread, and more fiber.
Cutting the amount of food you eat.
Eating out less often.
Spending at least one hour every day doing physical activity.

Healthcare professionals don't often prescribe medicine for children with prediabetes unless lifestyle changes don't lower blood sugar levels. Children who need medicine most often take metformin (Glumetza).

Alternative medicine

Some people believe that alternative therapies may treat or prevent type 2 diabetes. But there's no proof that alternative treatments work. Therapies that may help in type 2 diabetes that also are likely to be safe, include:

Aloe.
Blond psyllium.
Caffeine.
Flaxseed.
Ginseng.
Magnesium.
Oats.
Soy.
Xanthan gum.

Talk with your healthcare professional if you want to try dietary supplements or other alternative therapies to treat or prevent prediabetes. Some supplements or alternative therapies may be harmful if taken with some prescription medicines. Your healthcare professional can help you compare the pros and cons of alternative therapies you want to try.

Preparing for an appointment

Start by seeing your main healthcare professional, who may send you to a specialist in diabetes treatment, called an endocrinologist, and a dietitian or a diabetes educator.

Here's information to help you get ready for your appointment.

What you can do

When you call to make the appointment, ask what you need to do before you go. You may need to fast for at least eight hours before your appointment so that your healthcare professional can measure your fasting blood sugar level.

Make a list of:

Your symptoms, and when they began.
All medicines, vitamins and supplements you take, including dosages.
Key personal and medical information, including other conditions, recent life changes and stressors.
Questions to ask your healthcare professional.

Some basic questions to ask include:

How can I keep prediabetes from turning into type 2 diabetes?
Do I need to take medicine? If so, what side effects can I expect?
I have other health conditions. How can I best manage them together?
Should I not eat some foods? Can I still eat sugar?
Do I need to see a dietitian?
Are there local programs for preventing diabetes?

What to expect from your doctor

Your healthcare professional is likely to ask you questions, such as:

Has your weight changed recently?
Do you exercise regularly? If so, for how long and how often?
Do you have a family history of diabetes?