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Prediabetes is a condition in which blood sugar levels are higher than normal but not yet high enough to be diagnosed as type 2 diabetes. It is a warning sign rather than a sentence: prediabetes is common, often silent, and in many people it can be reversed or its progression delayed through lifestyle changes and, when appropriate, medication.
Prediabetes describes a state of impaired glucose regulation that sits between normal blood sugar control and type 2 diabetes. The body either does not respond to insulin as well as it should (insulin resistance), does not make quite enough insulin, or both. The result is glucose levels that are elevated but below the diabetes threshold.
Doctors recognize prediabetes through two overlapping patterns, sometimes present together (ADA, *Standards of Care in Diabetes*):
The medical term used in clinical records is prediabetes, coded as ICD-10 R73.03. It is a real, measurable metabolic state, not simply "almost having diabetes," and it carries its own health implications beyond diabetes risk, including an increased likelihood of cardiovascular disease.
Prediabetes is strikingly common. The CDC estimates that roughly 97.6 million U.S. adults — about 38% of the adult population — have prediabetes, and the figure rises to nearly half of adults aged 65 and older (CDC, *National Diabetes Statistics Report*). Critically, most people who have it do not know: in CDC surveillance data only about one in five adults with prediabetes report ever being told by a clinician that they have the condition. That gap between how common prediabetes is and how rarely it is recognized is one reason screening matters.
The central mechanism in most cases is insulin resistance. Insulin is the hormone that signals cells — especially in muscle, liver, and fat — to absorb glucose from the blood. When those cells respond poorly, the pancreas compensates by producing more insulin. For a while this keeps blood sugar normal, but when the pancreas can no longer keep up, glucose levels begin to creep upward, first into the prediabetes range and potentially into diabetes (NIH/NIDDK).
Insulin resistance is driven by a combination of genetics, body composition (particularly excess fat around the abdomen and within the liver), physical inactivity, and aging. It is closely linked to the cluster of findings known as metabolic syndrome — abdominal obesity, elevated blood pressure, high triglycerides, low HDL cholesterol, and elevated fasting glucose.
Major guidelines (ADA; USPSTF) identify the following as the strongest risk factors:
Some risk factors — family history, age, ethnicity, prior gestational diabetes — cannot be changed. Others, particularly weight, activity level, and diet, are modifiable, which is what makes prediabetes such an actionable diagnosis.
For most people, prediabetes has no noticeable symptoms at all. This is its defining clinical challenge: blood sugar can be elevated for years without producing any sensation the person can detect, which is why prediabetes is so often discovered incidentally on routine blood work or missed entirely.
Some people may notice a sign sometimes associated with insulin resistance called acanthosis nigricans — patches of darkened, velvety-textured skin, typically in the folds of the neck, armpits, or groin. This is more a marker of underlying insulin resistance than a symptom of high blood sugar itself.
When clear symptoms of high blood sugar do appear — excessive thirst, frequent urination, unexplained fatigue, blurred vision, or unintended weight loss — they generally indicate that glucose has already risen into the diabetes range rather than the prediabetes range. For that reason, these symptoms should prompt prompt medical evaluation, not reassurance.
Prediabetes is diagnosed with blood tests, because it cannot be reliably detected by symptoms. The American Diabetes Association recognizes three accepted tests, each with a defined prediabetes range (ADA, *Diagnosis and Classification of Diabetes*):
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Hemoglobin A1C | Below 5.7% | 5.7%–6.4% | 6.5% or higher |
| Fasting plasma glucose (FPG) | Below 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| 2-hour glucose (75 g OGTT) | Below 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
A few practical points help interpret these numbers:
Because of day-to-day biological variation, an abnormal result is generally confirmed with a repeat test, ideally the same test, before a diagnosis is finalized (ADA).
The U.S. Preventive Services Task Force (USPSTF) recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 who are overweight or have obesity (USPSTF, 2021 recommendation). The ADA similarly recommends testing all adults beginning at age 35, and testing at any age for those who are overweight and carry one or more additional risk factors. People with a history of gestational diabetes should be tested for life. If results are normal, repeat testing at least every three years is reasonable.
The cornerstone of managing prediabetes is lifestyle change first, supported by the strongest evidence in the field. Medication is added in selected higher-risk individuals. There is no over-the-counter drug proven to reverse prediabetes; supplements marketed for "blood sugar support" are not substitutes for the interventions below.
The landmark Diabetes Prevention Program (DPP), a large randomized trial funded by the NIH, showed that an intensive lifestyle program reduced progression from prediabetes to type 2 diabetes by 58% over about three years — and by 71% in adults aged 60 and older — compared with a placebo (standard-advice) control group (NIH/NIDDK; DPP Research Group). The benefit persisted for decades in long-term follow-up (DPPOS). The program's two central goals were:
These targets are achieved through realistic, sustainable changes: a diet emphasizing vegetables, whole grains, legumes, lean proteins, and healthy fats while reducing refined carbohydrates, sugary drinks, and ultra-processed foods; increased everyday movement; and adequate sleep. The CDC-recognized National Diabetes Prevention Program (National DPP) delivers this evidence-based curriculum through structured year-long programs that are widely available and often covered by insurance, including Medicare.
No medication is FDA-approved specifically to "treat prediabetes," but the ADA supports considering metformin — a biguanide that lowers glucose production by the liver and improves insulin sensitivity — for diabetes prevention in certain higher-risk adults. In the DPP, metformin reduced progression to diabetes by about 31% versus placebo, with the greatest benefit in younger adults, those with a higher BMI, those with higher fasting glucose, and women with a history of gestational diabetes (DPP Research Group; ADA). The ADA suggests metformin may be especially worth considering in adults roughly 25–59 years old with a BMI of 35 or higher, fasting glucose around 110 mg/dL or above, or A1C around 6.0% or higher, and in those with prior gestational diabetes (ADA, *Standards of Care*). Lifestyle change remains more effective than metformin in head-to-head data and is recommended for everyone regardless of whether medication is used.
Other glucose-lowering and weight medications — including GLP-1 receptor agonists (such as semaglutide and liraglutide) and the dual GIP/GLP-1 agonist tirzepatide — produce substantial weight loss and can improve glucose levels. Some are FDA-approved for chronic weight management or for type 2 diabetes, and emerging evidence shows they can delay progression to diabetes in people with obesity and prediabetes. They are not, however, standard first-line therapy specifically for prediabetes, and their use, cost, and appropriateness should be individualized with a clinician. Addressing related cardiovascular risk factors — blood pressure and cholesterol — is also a routine part of managing prediabetes, given its links to heart disease.
Yes. Prediabetes is one of the most modifiable conditions in medicine, and for many people it can be improved or returned to normal blood sugar levels. The same measures that prevent progression to diabetes — sustained modest weight loss, regular physical activity, and a quality diet — are also what keep it from advancing over the long term.
Long-term management is best thought of as an ongoing process rather than a one-time fix:
Reverting to normal glucose levels meaningfully lowers — though does not entirely eliminate — future diabetes risk, so continued healthy habits and periodic testing remain worthwhile even after improvement.
Because prediabetes is usually silent, the most important reason to see a clinician is proactive screening if you have any risk factors, even when you feel well. Beyond that, seek timely medical evaluation if you notice red-flag symptoms of high blood sugar, which may signal that glucose has progressed into the diabetes range:
You should also talk to a clinician if you have a personal history of gestational diabetes or PCOS, a strong family history of type 2 diabetes, or established heart disease, as these warrant earlier and more regular testing. A diagnosis of prediabetes is itself a reason to schedule a visit to discuss a personalized prevention plan and whether medication is appropriate.
Symptoms such as confusion, fruity-smelling breath, rapid breathing, severe abdominal pain, or vomiting are signs of a possible diabetes emergency and require urgent medical care.
The outlook for prediabetes is genuinely encouraging, particularly when it is identified and acted on. Without intervention, prediabetes commonly progresses: research summarized by the CDC and NIH indicates that a meaningful share of people with prediabetes develop type 2 diabetes within several years, and a substantial proportion will develop it over their lifetime. Prediabetes also independently raises the risk of heart disease and stroke.
The reassuring counterpoint is that this trajectory is not fixed. Lifestyle intervention can cut the risk of developing type 2 diabetes by more than half, with even larger benefits in older adults, and these effects can last for many years (NIH/NIDDK; DPP/DPPOS). Many people return their blood sugar to the normal range. The key determinants of outcome are early detection and sustained change — which is precisely why screening, awareness, and consistent follow-up matter so much for a condition that so often hides in plain sight.
Can prediabetes be reversed? For many people, yes. Through sustained weight loss of around 5%–7% of body weight and regular physical activity, blood sugar can return to the normal range, and the risk of progressing to type 2 diabetes drops substantially (NIH/NIDDK; DPP). "Reversal" does not guarantee blood sugar will stay normal permanently, so continued healthy habits and periodic testing remain important even after improvement.
Does having prediabetes mean I will definitely get diabetes? No. Prediabetes raises the risk but is not a certainty. A significant proportion of people progress to type 2 diabetes over time if nothing changes, but lifestyle intervention can prevent or delay that progression in more than half of cases (DPP). It is best viewed as an early warning and an opportunity to intervene.
What A1C level means prediabetes? An A1C between 5.7% and 6.4% is in the prediabetes range, according to the ADA. Below 5.7% is considered normal, and 6.5% or higher on two tests is consistent with diabetes. Because A1C reflects average blood sugar over the prior 2–3 months, a single borderline value is typically confirmed with a repeat test.
Should I take metformin for prediabetes? Lifestyle change is the recommended first step for everyone. Metformin is not appropriate for all people with prediabetes, but the ADA supports considering it for certain higher-risk adults — for example, younger adults with higher BMI, higher fasting glucose, or a history of gestational diabetes (ADA). Whether metformin is right for you is a decision to make with a clinician.
Is prediabetes related to diet and sugar alone? Not entirely. Diet matters, but prediabetes is driven primarily by insulin resistance, which is influenced by genetics, body weight and fat distribution, physical activity, and age — not by sugar intake alone. A thin or active person can develop prediabetes, and dietary improvement is most effective when combined with physical activity and, where needed, weight loss.
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*This page is for general education and is not medical advice. Prediabetes is a medical condition that should be diagnosed and managed by a qualified healthcare professional. Always consult your clinician before starting, stopping, or changing any treatment, and seek prompt care for any concerning symptoms.*
There is no FDA-approved medication specifically labeled to "treat prediabetes." The most evidence-based intervention is a structured lifestyle change program: in the NIH-funded Diabetes Prevention Program (DPP) randomized trial, intensive lifestyle change (modest weight loss of 5-7% plus about 150 minutes of activity per week) cut the roughly 3-year risk of developing type 2 diabetes by 58% (71% in adults age 60 and older). The CDC-recognized National Diabetes Prevention Program delivers this curriculum nationwide. Metformin, an FDA-approved diabetes drug, is sometimes prescribed off-label for prevention in higher-risk people; in the DPP it reduced risk by 31%. The American Diabetes Association suggests metformin may be considered especially in adults at high risk, such as those aged 25-59 with a BMI of 35 or higher, higher fasting glucose or A1C, or a history of gestational diabetes. Any medication decision should be made with a licensed clinician. This information is educational and is not medical advice.
Yes, prediabetes can often be reversed, meaning blood sugar levels can return to the normal range, though it is better described as reversible than permanently "cured" because the underlying tendency toward high blood sugar can return. In the landmark Diabetes Prevention Program study, losing 5-7% of body weight and getting about 150 minutes of moderate activity per week reduced progression to type 2 diabetes by 58% over three years. Even after blood sugar normalizes, ongoing healthy habits and periodic testing are important to keep it from coming back. Talk to a clinician to build a plan suited to your situation.
Prediabetes usually has no noticeable symptoms, which is why most people who have it do not know it. In some cases, a sign called acanthosis nigricans, darkened, velvety patches of skin on the neck, armpits, or groin, can appear. Symptoms such as increased thirst, frequent urination, fatigue, or blurred vision generally signal that blood sugar has risen into the diabetes range rather than prediabetes. Because it is often silent, screening with a blood test is the only reliable way to detect it.
Prediabetes is driven mainly by insulin resistance, in which the body's muscle, fat, and liver cells stop responding well to insulin, so blood sugar rises. This typically results from a combination of genetics and lifestyle factors rather than a single cause. Common contributors and risk factors include excess weight (especially around the abdomen), physical inactivity, a diet high in processed foods and sugar, a family history of type 2 diabetes, age 45 or older, gestational diabetes, PCOS, and certain racial or ethnic backgrounds. A clinician can assess your personal risk factors.
According to American Diabetes Association criteria, prediabetes is defined by an A1C of 5.7% to 6.4%, a fasting blood glucose of 100 to 125 mg/dL, or a 2-hour glucose of 140 to 199 mg/dL on an oral glucose tolerance test. Values below these (A1C under 5.7% or fasting glucose under 100 mg/dL) are considered normal, while values at or above an A1C of 6.5% or fasting glucose of 126 mg/dL indicate diabetes. A single result is usually confirmed with a repeat test. Only a healthcare provider can interpret your results and make a diagnosis.
Prediabetes is diagnosed with a blood test, most commonly the A1C test, which reflects average blood sugar over about three months and does not require fasting. Other options are a fasting plasma glucose test, which requires not eating for at least 8 hours, and an oral glucose tolerance test, which measures blood sugar before and two hours after drinking a glucose solution. Because it usually causes no symptoms, screening is recommended for adults who are overweight with additional risk factors, and routinely starting at age 45. A clinician will choose and interpret the appropriate test for you.
The first-line treatment for prediabetes is lifestyle change: losing about 5-7% of body weight, eating a diet rich in whole foods with less added sugar and refined carbohydrates, and getting at least 150 minutes of moderate physical activity per week. These steps were shown in clinical research to cut the risk of developing type 2 diabetes by more than half. For some people, especially those with a higher A1C, obesity, or a history of gestational diabetes, a clinician may also prescribe the medication metformin. A healthcare provider can recommend the right combination for you.
No, prediabetes does not always progress to type 2 diabetes, and the right steps can significantly lower that risk or even return blood sugar to normal. Without intervention, however, a substantial share of people with prediabetes go on to develop type 2 diabetes over the following years, which is why it is considered an important warning sign. Lifestyle changes and, in some cases, metformin have been shown to delay or prevent that progression. Regular follow-up testing with a clinician helps catch any worsening early.
There is no fixed timeline, but many people see meaningful improvement in blood sugar within a few months of consistent diet, exercise, and modest weight loss. A1C reflects roughly three months of blood sugar, so it is often rechecked after about three to six months to gauge progress. Sustaining the changes matters more than speed, since stopping healthy habits can allow levels to drift back up. Your clinician can set realistic goals and schedule follow-up testing to track your results.
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This page is for general information and is not medical advice. Always consult a qualified clinician about diagnosis and treatment. Individual results vary.