ConditionHormones & metabolism
Prediabetes
Prediabetes means your blood sugar is higher than normal but not high enough to be type 2 diabetes: an A1C of 5.7% to 6.4%, or a fasting glucose of 100 to 125 mg/dL (5.6 to 6.9 mmol/L). About 1 in 3 US adults has it, and most do not know because it rarely causes symptoms. Without changes, many go on to develop type 2 diabetes. Losing 5% to 7% of body weight and getting 150 minutes of activity a week cuts that risk by more than half.
Also called: Impaired glucose tolerance, impaired fasting glucose, borderline diabetes, intermediate hyperglycemia
At a glance
- What it is
- Blood sugar above normal but below the diabetes threshold.
- Diagnostic ranges
- A1C 5.7% to 6.4%; fasting glucose 100 to 125 mg/dL; 2-hour glucose tolerance 140 to 199 mg/dL.
- How common
- About 1 in 3 US adults; over 80% are unaware.
- Symptoms
- Usually none; sometimes darkened skin folds (acanthosis nigricans).
- Risks
- Type 2 diabetes, heart disease, stroke, fatty liver.
- Treatment
- Weight loss, physical activity, healthy diet, Diabetes Prevention Program; metformin for some.
When to get help
Call 911 or go to the ER
- Extreme thirst, frequent urination, vomiting, deep fast breathing or confusion (possible very high blood sugar)
See a doctor within a day or two
- New excessive thirst, frequent urination, blurred vision and unexplained weight loss (possible diabetes)
- Fasting glucose of 126 mg/dL (7.0 mmol/L) or higher, or A1C of 6.5% or higher
Book a routine appointment
- A1C of 5.7% to 6.4% or fasting glucose of 100 to 125 mg/dL on a blood test
- Age 35 to 70 and overweight: ask about screening
- History of gestational diabetes or polycystic ovary syndrome
- Dark, velvety patches on the neck or armpits
What prediabetes means
After you eat, insulin from the pancreas moves sugar from the blood into cells. In prediabetes, cells respond less well to insulin (insulin resistance), and the pancreas gradually struggles to keep up. Blood sugar rises above normal. Damage to blood vessels and organs can begin even at this stage.
Prediabetes numbers
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| A1C (average sugar over 2 to 3 months) | Below 5.7% | 5.7% to 6.4% | 6.5% or higher |
| Fasting plasma glucose | Below 100 mg/dL (5.6 mmol/L) | 100 to 125 mg/dL (5.6 to 6.9 mmol/L) | 126 mg/dL (7.0 mmol/L) or higher |
| 2-hour oral glucose tolerance test | Below 140 mg/dL (7.8 mmol/L) | 140 to 199 mg/dL (7.8 to 11.0 mmol/L) | 200 mg/dL (11.1 mmol/L) or higher |
The World Health Organization uses a slightly higher fasting cutoff (110 mg/dL) for impaired fasting glucose. A diagnosis is usually confirmed with a repeat test.
Symptoms
Most people have no symptoms. Possible signs:
- acanthosis nigricans: dark, velvety skin on the neck, armpits or groin, a sign of insulin resistance
- skin tags
- tiredness
If you develop increased thirst, frequent urination, blurred vision or unexplained weight loss, you may have progressed to type 2 diabetes.
Risk factors
- overweight or obesity, especially around the waist
- age 35 or older
- physical inactivity
- family history of type 2 diabetes
- history of gestational diabetes or a baby over 9 lb (4 kg)
- polycystic ovary syndrome
- high blood pressure, low HDL cholesterol or high triglycerides
- fatty liver disease
- sleep apnea and short sleep
- Black, Hispanic/Latino, American Indian, Alaska Native, Asian American and Pacific Islander backgrounds have higher rates
- long-term steroids and some antipsychotics
Who should be tested
- The USPSTF recommends screening adults aged 35 to 70 who are overweight or obese, every 3 years if normal.
- The ADA recommends testing all adults from age 35, and earlier for those who are overweight with other risk factors.
- Women with past gestational diabetes should be tested at least every 3 years.
What happens without treatment
Without lifestyle change, a substantial share of people with prediabetes develop type 2 diabetes within 5 to 10 years. Prediabetes also raises the risk of heart disease, stroke, kidney disease and fatty liver disease, and is often part of metabolic syndrome.
How to reverse prediabetes
The landmark Diabetes Prevention Program trial showed that lifestyle changes reduced the risk of developing type 2 diabetes by 58% over 3 years, and by 71% in people over 60.
Lose 5% to 7% of body weight
For someone weighing 200 lb (91 kg), that is 10 to 14 lb (4.5 to 6.5 kg). Weight around the waist matters most.
Move more
- at least 150 minutes a week of moderate activity, such as brisk walking (30 minutes, 5 days a week)
- strength training twice a week
- break up long periods of sitting; a short walk after meals lowers blood sugar
Eat for steady blood sugar
- fill half your plate with non-starchy vegetables
- choose whole grains, beans and lentils over white bread, white rice and pastries
- cut sugary drinks, including juice and sweetened coffee
- include lean protein and healthy fats (fish, nuts, olive oil)
- watch portion sizes
- Mediterranean, DASH and lower-carbohydrate eating patterns all work if sustainable
Other habits
- sleep 7 to 9 hours
- stop smoking, which raises diabetes risk
- limit alcohol
- manage stress
Join a program
The CDC's National Diabetes Prevention Program offers year-long lifestyle coaching, in person or online, often covered by insurance and Medicare.
Medicines
Metformin may be recommended for people at highest risk, especially those under 60 with a BMI of 35 or more, an A1C near 6.4%, or a history of gestational diabetes. It reduced diabetes risk by about 31% in the DPP. Weight-loss medicines can also help eligible people.
Monitoring
- repeat A1C or fasting glucose at least yearly
- check blood pressure and cholesterol
- see your doctor if symptoms of diabetes appear
Frequently asked questions
What A1C level is prediabetes?
An A1C of 5.7% to 6.4% indicates prediabetes. Below 5.7% is normal, and 6.5% or higher on two tests indicates diabetes. A fasting glucose of 100 to 125 mg/dL also indicates prediabetes.
Can prediabetes be reversed?
Yes. Many people return blood sugar to normal by losing 5% to 7% of their body weight, exercising at least 150 minutes a week and eating a healthier diet. Lifestyle changes cut the risk of type 2 diabetes by more than half.
What are the symptoms of prediabetes?
Prediabetes usually has no symptoms. Some people notice dark, velvety patches of skin on the neck or armpits. Because it is silent, blood tests are the only reliable way to find it.
What should I eat if I have prediabetes?
Focus on non-starchy vegetables, whole grains, beans, lean proteins and healthy fats, and cut back on sugary drinks, refined carbohydrates and processed foods. Smaller portions and regular meals help. A dietitian can tailor a plan.
How long does it take to reverse prediabetes?
Some people see improvements in blood sugar within a few months of weight loss and increased activity. Because A1C reflects about 3 months of blood sugar, retesting after 3 to 6 months shows progress.
Does prediabetes always turn into diabetes?
No. Many people with prediabetes never develop type 2 diabetes, especially if they make lifestyle changes. Without changes, though, the risk is high, so prediabetes is an important warning sign.
Sources
This guide was written from current patient and clinical guidance, including:
- American Diabetes Association: Standards of Care in Diabetes (2025), classification and diagnosis
- CDC: Prediabetes, your chance to prevent type 2 diabetes; National Diabetes Prevention Program
- US Preventive Services Task Force: Screening for prediabetes and type 2 diabetes (2021)
- NIDDK: Diabetes Prevention Program (DPP) results
- MedlinePlus: Prediabetes