Prediabetes means your blood sugar is higher than normal but not yet high enough to be called type 2 diabetes. It is extremely common: more than 1 in 3 American adults have it, and most of them do not know. The good news is that prediabetes is one of the most reversible conditions in medicine. This guide covers prediabetes symptoms, the test results that confirm it and the specific habits shown to bring blood sugar back to normal.
Key takeaways
- Prediabetes usually causes no obvious symptoms; a blood test is the only reliable way to find it.
- It is diagnosed with an A1C of 5.7–6.4%, a fasting glucose of 100–125 mg/dL, or a 2-hour glucose test of 140–199 mg/dL.
- Losing 5–7% of body weight and exercising 150 minutes a week cut progression to diabetes by 58% in a landmark trial.
What happens in the body with prediabetes?
After you eat, insulin moves glucose from the blood into your cells. In prediabetes, cells respond less well to insulin (insulin resistance), so the pancreas has to produce more of it to keep blood sugar in check. Over time, the pancreas struggles to keep up and glucose levels creep upward. Excess fat around the abdomen, inactivity and genetics are the biggest drivers of insulin resistance.
Prediabetes symptoms and warning signs
Most people feel completely normal. When signs do appear, they are often subtle:
- Darkened skin patches (acanthosis nigricans) on the neck, armpits, elbows or knuckles, a visible sign of insulin resistance.
- Skin tags, especially many of them around the neck or armpits.
- Weight gain around the waist, even if overall weight looks “normal.”
- Feeling sleepy or foggy after carb-heavy meals.
- Irregular periods or polycystic ovary syndrome (PCOS), which is closely linked to insulin resistance.
Classic diabetes symptoms such as intense thirst, frequent urination, blurred vision and slow-healing cuts suggest blood sugar may have already crossed into the diabetes range. If you notice these, see a doctor soon.
How prediabetes is diagnosed
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| A1C | Below 5.7% | 5.7–6.4% | 6.5% or higher |
| Fasting plasma glucose | Below 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| 2-hour oral glucose tolerance test | Below 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
The A1C test reflects your average blood sugar over roughly three months and does not require fasting, which makes it the most convenient screening test.
Who should get tested?
- All adults aged 35 and older.
- Younger adults who are overweight and have another risk factor, such as a parent or sibling with type 2 diabetes, high blood pressure, low HDL cholesterol, physical inactivity, PCOS or a history of gestational diabetes.
- People of African American, Hispanic/Latino, Native American, Asian American or Pacific Islander background, who face higher risk at lower body weights.
How to reverse prediabetes: what the evidence shows
The US Diabetes Prevention Program followed more than 3,000 adults with prediabetes. Those who lost about 7% of their body weight and exercised 150 minutes a week reduced their risk of developing diabetes by 58%, and by 71% in people over 60. That was nearly twice as effective as the drug metformin.
1. Lose a modest amount of weight
For someone weighing 90 kg (200 lb), 5–7% is about 4.5–6.5 kg (10–14 lb). Losing weight from around the middle has the biggest effect on insulin sensitivity. Our guide to losing belly fat safely explains how.
2. Move for 150 minutes a week
Brisk walking counts. Working muscles pull glucose out of the blood even without extra insulin. A 10–15 minute walk after meals is a simple way to blunt blood sugar spikes. Add two sessions of strength training a week to build muscle, your body’s biggest glucose “sink.”
3. Change what is on your plate
- Fill half your plate with non-starchy vegetables, a quarter with lean protein and a quarter with whole grains or beans.
- Swap sugary drinks and juice for water, unsweetened tea or coffee.
- Choose high-fiber foods; fiber slows the absorption of sugar.
- Cut back on refined carbs such as white bread, pastries and sweets.
4. Protect your sleep and manage stress
Even a few nights of short sleep make cells measurably more insulin resistant. Chronic stress raises cortisol, which raises blood sugar. Aim for 7–9 hours a night and get checked for sleep apnea if you snore loudly.
5. Quit smoking
Smokers are 30–40% more likely to develop type 2 diabetes than non-smokers.
How long does it take to reverse prediabetes?
Fasting glucose and how you feel after meals can improve within weeks of consistent changes. Because A1C reflects about three months of blood sugar, most doctors re-test after three to six months. Keep the habits going afterwards; prediabetes can return if old patterns come back.
Frequently asked questions
Does prediabetes always turn into diabetes?
No. Without changes, a significant share of people with prediabetes develop type 2 diabetes within five to ten years, but many can return to normal blood sugar with lifestyle changes.
Can thin people have prediabetes?
Yes. Genetics, inactivity and fat stored around the organs (visceral fat) can cause insulin resistance even at a normal body weight.
Do I need medication for prediabetes?
Most people start with lifestyle changes. Doctors sometimes add metformin for people at very high risk, such as those with a BMI over 35, a history of gestational diabetes, or rising A1C despite lifestyle efforts.
Medical disclaimer: This article is for general education only and is not a substitute for personal medical advice, diagnosis or treatment. Talk to your doctor about blood sugar testing and before making major changes to your diet, exercise or medication.
