Being prediabetic means your blood sugar is higher than normal but not yet high enough to qualify as type 2 diabetes. It’s a warning stage, not a diagnosis of diabetes itself, and it’s remarkably common: more than 115 million American adults have prediabetes, and 8 in 10 of them don’t know it. The good news is that prediabetes is reversible with changes that are well-studied and straightforward.
What’s Happening Inside Your Body
To understand prediabetes, it helps to know what insulin does. When you eat, your body breaks food down into blood sugar (glucose). Your pancreas releases insulin, a hormone that acts like a key, unlocking your cells so glucose can enter and be used for energy. In a healthy system, this process keeps blood sugar within a narrow range.
With prediabetes, your cells start ignoring insulin’s signal. This is called insulin resistance. When cells stop responding well, glucose builds up in your bloodstream instead of entering your cells. Your pancreas tries to compensate by producing more and more insulin, but over time it can’t keep up with the demand. The result is blood sugar that creeps steadily upward. Prediabetes is essentially the phase where your body is struggling to maintain normal blood sugar but hasn’t completely lost the battle yet.
How Prediabetes Is Diagnosed
Prediabetes is identified through blood tests. The most common is the A1C test, which measures your average blood sugar over the previous two to three months. The ranges break down simply:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
Your doctor may also use a fasting blood sugar test, which checks your glucose level after you haven’t eaten for at least eight hours. A fasting level between 100 and 125 mg/dL falls in the prediabetic range. A third option, the oral glucose tolerance test, measures blood sugar two hours after drinking a sugary solution. A reading between 140 and 199 mg/dL indicates prediabetes. Any of these tests can confirm the diagnosis, and your doctor may repeat the test to be sure.
Why Most People Don’t Realize They Have It
Prediabetes rarely produces obvious symptoms. You won’t necessarily feel tired, thirsty, or different in any noticeable way. That’s the main reason 8 out of 10 people with prediabetes are unaware of their condition. It’s typically caught during routine bloodwork, not because someone walks in with complaints.
There is one visible clue worth knowing about. Some people with insulin resistance develop patches of dark, velvety skin in body creases like the neck, armpits, or groin. This condition, called acanthosis nigricans, is a direct sign that your body is producing excess insulin. It’s more common in people who carry extra weight. If you notice these patches, it’s worth asking your doctor about a blood sugar check even if you feel fine otherwise.
Who Gets Screened
The U.S. Preventive Services Task Force recommends screening adults aged 35 to 70 who are overweight or obese. Carrying excess weight is the single strongest risk factor for developing prediabetes and type 2 diabetes. But weight isn’t the only factor. Others include:
- Family history: a parent or sibling with type 2 diabetes
- History of gestational diabetes: diabetes that developed during pregnancy
- Polycystic ovarian syndrome (PCOS)
- Age: risk increases as you get older
- Sedentary lifestyle and dietary patterns
Certain racial and ethnic groups face disproportionately higher rates, including American Indian/Alaska Native, Asian American, Black, Hispanic/Latino, and Native Hawaiian/Pacific Islander populations. Screening guidelines recommend starting earlier for people in these groups. For Asian Americans specifically, screening is recommended at a lower body mass index of 23 or above, compared to 25 for the general population.
The Risk of Progressing to Diabetes
Prediabetes doesn’t always turn into type 2 diabetes, but without intervention, the odds are substantial. Research published in BMJ Open Diabetes Research & Care found that at age 45, a person with prediabetes faces roughly a 10 to 25% chance of developing diabetes within the next decade, depending on how prediabetes is defined and measured. The lifetime risk is much higher: around 46 to 58% for men and 58 to 80% for women.
These numbers are not a guarantee. They represent what happens when nothing changes. The trajectory can shift significantly with lifestyle modifications, which is what makes prediabetes different from many other health conditions. It gives you a window to act before permanent damage occurs.
How to Reverse It
The landmark Diabetes Prevention Program trial established a clear, evidence-based formula for reducing diabetes risk. Participants who lost 7% of their body weight and exercised at moderate intensity for about two and a half hours per week reduced their risk of developing type 2 diabetes by 58%. For someone weighing 200 pounds, that’s a 14-pound loss. The exercise target translates to roughly 30 minutes of brisk walking five days a week.
That 58% reduction was more effective than medication in the trial. And the weight loss didn’t need to happen overnight. Participants worked toward their goal gradually over the first six months of the program. The key was sustaining both the weight loss and the activity level over time.
In practical terms, the changes that matter most are the ones that lower your blood sugar on a daily basis. Reducing refined carbohydrates and added sugars, eating more vegetables and whole grains, moving your body regularly, and losing a modest amount of weight all improve how your cells respond to insulin. You don’t need to reach an ideal weight or run marathons. Even small, consistent changes measurably improve blood sugar control.
What Prediabetes Doesn’t Mean
A prediabetes diagnosis does not mean you will definitely get diabetes. It does not mean you need insulin or medication right away. It means your body is sending a clear, early signal that your blood sugar regulation is under strain. Many people bring their A1C back below 5.7% with lifestyle changes alone and stay there for years.
It’s also worth understanding that prediabetes itself carries some health risks beyond the possibility of progressing to diabetes. Chronically elevated blood sugar, even in the prediabetic range, is associated with increased risk of heart disease and stroke. Addressing it isn’t just about preventing a future diabetes diagnosis. It’s about protecting your cardiovascular health right now.