Prediabetic means your blood sugar is higher than normal but not high enough to qualify as type 2 diabetes. It’s a warning stage, not a diagnosis of diabetes, and it affects an estimated 115 million American adults. The good news: prediabetes can often be reversed with lifestyle changes before it progresses further.
What Happens in Your Body
Your body normally uses a hormone called insulin to move sugar from your blood into your cells, where it gets used for energy. In prediabetes, your cells stop responding to insulin as well as they should. This is called insulin resistance, and it typically starts in your muscles, fat, and liver.
When your cells resist insulin’s signal, your pancreas tries to compensate by producing more of it. For a while, that extra output keeps your blood sugar in check. But over time, your pancreas can’t keep up with the demand. Sugar starts building up in your bloodstream, pushing your levels into the prediabetic range. If that process continues unchecked, it eventually crosses the threshold into type 2 diabetes.
The Numbers That Define Prediabetes
Three common blood tests can identify prediabetes, and each has a specific range:
- A1C: 5.7% to 6.4%. This test reflects your average blood sugar over the past two to three months. Normal is below 5.7%, and diabetes starts at 6.5%.
- Fasting blood glucose: 100 to 125 mg/dL. This is a snapshot of your blood sugar after not eating overnight. Normal is below 100 mg/dL, and 126 mg/dL or higher indicates diabetes.
- Oral glucose tolerance test: 140 to 199 mg/dL two hours after drinking a sugary solution. Normal is below 140 mg/dL, and 200 mg/dL or higher means diabetes.
You only need one of these tests to come back in the prediabetic range for the label to apply, though your doctor may use more than one to confirm.
Who Is Most at Risk
The U.S. Preventive Services Task Force recommends screening for prediabetes in adults aged 35 to 70 who are overweight (BMI of 25 or higher) or obese (BMI of 30 or higher). That starting age was recently lowered from 40 to 35 to catch more cases early.
Certain populations face higher risk and may need screening even younger. Black, Hispanic/Latino, American Indian/Alaska Native, and Native Hawaiian/Pacific Islander adults all have disproportionately high rates of diabetes. For Asian Americans, screening is recommended at a lower BMI threshold of 23, because differences in body composition mean standard BMI cutoffs underestimate their actual risk.
Beyond weight and ethnicity, other factors that raise your chances include a family history of diabetes, a personal history of gestational diabetes (diabetes during pregnancy), polycystic ovarian syndrome (PCOS), and older age.
Symptoms You Might Notice
Prediabetes itself rarely causes obvious symptoms, which is why most people don’t know they have it. But insulin resistance can produce one visible sign worth knowing about: patches of dark, thick, velvety skin in body folds and creases, most commonly in the armpits, groin, and back of the neck. This condition, called acanthosis nigricans, sometimes comes with itching or small skin tags in the same areas. If you notice these changes, it’s a reason to get your blood sugar checked.
Other subtle signs people sometimes report, like increased thirst, more frequent urination, or fatigue, tend to overlap with many other conditions and aren’t reliable indicators on their own. Blood testing is the only way to know for sure.
How Likely It Is to Become Diabetes
Prediabetes does not automatically turn into type 2 diabetes, but the long-term odds are significant if nothing changes. A study published in BMJ Open Diabetes Research & Care found that among 45-year-olds with prediabetes, the remaining lifetime risk of developing diabetes was roughly 58% for women and 46% for men. Over a shorter window of 10 years, the risk was lower but still meaningful: about 14% for women and 9% for men at that age.
Those numbers are averages. Your individual risk depends on where your blood sugar falls within the prediabetic range, your weight, your activity level, and whether you make changes after the diagnosis.
Reversing Prediabetes With Lifestyle Changes
The strongest evidence for reversing prediabetes comes from the Diabetes Prevention Program, a landmark study that the CDC later turned into a national program. The results were striking: people who lost 5 to 7 percent of their body weight and exercised at least 150 minutes per week reduced their risk of developing type 2 diabetes by 58 percent. For someone weighing 200 pounds, that’s a loss of just 10 to 14 pounds.
The 150 minutes per week doesn’t need to be intense. Brisk walking counts. Spread across five days, that’s 30 minutes a day. The key finding was that modest, sustainable changes outperformed aggressive short-term diets.
On the food side, the program focused on overall calorie reduction rather than eliminating specific food groups. Practical shifts that help include replacing refined carbohydrates (white bread, sugary drinks, processed snacks) with whole grains, vegetables, and legumes, which release sugar into your bloodstream more slowly. Eating more fiber-rich foods and fewer foods that cause rapid blood sugar spikes makes a measurable difference in how your body handles insulin over time.
When Medication Comes Into Play
Lifestyle changes are the first-line approach, but the American Diabetes Association’s 2024 guidelines note that medication may be considered for people at particularly high risk of progressing to diabetes. That generally means adults aged 25 to 59 with a BMI of 35 or higher, fasting glucose of 110 mg/dL or above, an A1C of 6.0% or higher, or a history of gestational diabetes. In these cases, medication works alongside diet and exercise rather than replacing them.
What to Expect After a Prediabetes Diagnosis
If your blood work comes back in the prediabetic range, the most important thing to understand is that you’re in a window where the trajectory can still change. This isn’t a one-time test and forget situation. Regular follow-up testing lets you and your doctor track whether your numbers are moving in the right direction, holding steady, or creeping toward diabetes.
Many people who take the lifestyle changes seriously see their blood sugar return to normal levels. Prediabetes is one of the few conditions where catching it early and acting on it can genuinely erase the problem rather than just manage it.