Type 2 diabetes, in which the body doesn’t use insulin properly, is on the rise in the United States. There are more than 35 million people with the condition, and many are diagnosed when they are young, even in adolescence. Perhaps more astonishing—and worrying—is that prediabetes, the condition that leads to type 2 diabetes, now affects 96 million people. That’s one in three of us.
The good news is that prediabetes can be seen as a warning sign—it’s the body’s way of saying that your insulin levels are rising, but you can still reverse it before developing type 2 diabetes.
And reversing the process is key because type 2 diabetes can be a devastating disease. The condition usually begins with insulin resistance, in which the fat, liver, and muscle cells do not use insulin properly, so that eventually the body needs more insulin than it can produce, causing blood glucose to rise. And those elevated levels can lead to a number of serious health issues if they are not managed properly.
The problem is that you may not even know you have prediabetes or diabetes—you can be symptom-free for years. But once the complications of diabetes start to occur, nearly every aspect of your health can be affected. That’s because the excessive sugar in your blood is damaging to blood vessels and nerves throughout your body.
So, how do you know if you have prediabetes? Can children get it? How can you reverse it?
Below, Yale Medicine experts answer these commonly asked questions (and more) about prediabetes.
What happens when prediabetes becomes type 2 diabetes?
It’s important to note that type 2 diabetes is different from type 1 diabetes, a condition in which the body produces little to no insulin, resulting in high blood glucose levels. In people with type 2 diabetes, the body’s cells don’t respond properly to insulin, and glucose doesn’t move efficiently from the bloodstream into the cells. This is known as insulin resistance. As a result, the level of glucose in the blood rises. The pancreas will initially respond by producing more insulin, but it will, inevitably, not be able to keep up, resulting in high blood glucose levels, or a condition called hyperglycemia, which can lead to a number of serious health issues, including blindness, heart attack, stroke, kidney failure, and amputations of the feet, legs, or toes, if it is not managed properly.
But prediabetes itself is a serious health issue. “Prediabetes goes hand in hand with metabolic syndrome, the term for a condition that includes hypertension, obesity, and high cholesterol,” says Yale Medicine endocrinologist Anika Anam, MD. Each of those conditions raises the risk for serious issues, such as heart disease, stroke, and cancer.
In people with prediabetes, some of the long-term damage to the blood vessels, heart, and kidneys may already be starting. The condition has also been linked to what are called “silent” heart attacks, with symptoms so mild people may not realize they occurred.
How do you know if you have prediabetes?
The first step is to know the risk factors, which can help determine whether or not you should be screened for the condition. Without screening, early signs of insulin resistance can be hard to identify—a person can have prediabetes for years without knowing it. “Symptoms that are associated with type 2 diabetes, such as increased urination, won’t necessarily surface with prediabetes,” says Dr. Anam.
Obesity, an underlying cause of insulin resistance, is a major risk factor. A study published in 2020 found that participants who had obesity were about six times more likely to develop type 2 diabetes than those at a healthy weight, regardless of genetic predisposition; people who were overweight had 2.4 times the normal risk.
Other common risk factors for prediabetes include being older than 45, exercising fewer than three times a week, having a parent or sibling with (or a family history of) type 2 diabetes, and giving birth to a baby that weighed more than 9 pounds. Women who have polycystic ovary syndrome (PCOS), a hormonal disorder, are also at higher risk for the condition.
However, risk can be complicated for some people. For instance, there are some people with obesity who don’t develop obesity-related diseases, and others who develop type 2 diabetes without being overweight, Dr. Anam explains. “But if you are overweight and struggling to lose weight, if you’re not physically active, and if you have other health problems, like high blood pressure and high cholesterol, you are at risk,” she says.
Anyone who is not sure about their risk can take a simple online prediabetes test provided by the Centers for Disease Control and Prevention (CDC).
Are there tests that can diagnose prediabetes?
Yes, the following blood tests can diagnose the condition:
- A1C test measures blood sugar over the past two to three months (and it’s the easiest test, since it’s not necessary to fast beforehand). A result in the range of 5.7%–6.4% indicates prediabetes.
- Fasting blood sugar test measures blood sugar after an overnight fast. A result of 100–125 mg/dL indicates prediabetes.
- Glucose tolerance test measures blood sugar before and after drinking a glucose liquid. A result of 140–199 mg/dL indicates prediabetes.
Is there a higher risk for prediabetes at certain times in life?
For those who are diagnosed with or concerned they might be at risk for prediabetes, “the first thing to do is focus on weight loss and dietary changes,” says Dr. Anam. This isn’t always easy, and stress can interrupt lifestyle management in different ways, depending on a person’s situation and stage in life, whether it’s during adolescence, pregnancy, menopause, or even retirement.
Problems with insulin often start around puberty, says Yale Medicine endocrinologist Ania Jastreboff, MD, PhD, who treats both children and adults. But there are other factors, too, adds Dr. Anam. “The big thing I’ve seen at this age is a lot of anxiety and depression, disordered eating behaviors, sedentary behavior, and excessive interaction with social media,” says Dr. Anam.
Pregnancy can also lead to struggles with weight for many women. Gestational diabetes, which usually resolves after the baby is born, is another prediabetes trigger. And around menopause, changes in estrogen levels are associated with an increase in fat around the waist, which is considered a risk factor for diabetes.
In general, those who maintain good physical health as they age can avoid prediabetes. “But as you get older, you may develop joint pain, which can limit physical activity,” says Dr. Anam, so it’s important to pay attention to those issues.
Heart disease can also impact physical activity, as can the use of multiple medications, including medicines like glucocorticoids—steroids that, among other things, increase insulin resistance and glucose production by the liver, resulting in increased blood glucose levels. They can also make people who take them feel hungrier, which leads to increased food intake and further contributes to hyperglycemia. “All these things add up,” she says.
Can children get prediabetes?
Yes. The CDC reports that 18% of adolescents have prediabetes, and it’s on the rise in that group.
All children experience metabolic and hormonal changes during puberty, along with a decrease in insulin sensitivity; problems tend to develop when an adolescent also has obesity, explains Dr. Jastreboff. “Children who have obesity are much more likely to grow up to be adults who have obesity, and then they are likely to develop weight-related diseases like type 2 diabetes, kidney problems, and heart problems,” she says.
Lifestyle changes are critical to prevention in kids, because there are no effective medications for reversing prediabetes in that age group, says Michelle Van Name, MD, a Yale Medicine pediatric endocrinologist. “And we know that prediabetes and type 2 diabetes are more aggressive in kids than they are in adults.”
Dr. Jastreboff also points out that in the “Treatment Options for Type 2 Diabetes in Adolescents and Youth” (TODAY) study, a major clinical trial funded by the National Institutes of Health (NIH), youth who developed type 2 diabetes at a young age had more severe cases than adults with the disease.
How much weight do you need to lose to reverse prediabetes?
There are many people with prediabetes who need to take action now—if they don’t, they could develop type 2 diabetes within five years, according to the CDC.
And although weight loss is a key strategy, it’s important to know that not everyone needs to lose a massive amount of weight, doctors say. “Often only minor changes in dietary intake and minimal weight loss, together with more physical activity, will help chase diabetes away,” says Sonia Caprio, MD, a Yale Medicine pediatric endocrinologist.
The CDC’s national Diabetes Prevention Program (DPP), which includes an ongoing Outcomes Study, has shown that people with prediabetes who lost a modest amount of weight—5 to 7% (10 to 14 pounds for a person weighing 200 pounds, for example)—with the help of a structured lifestyle-change program cut their risk of developing type 2 diabetes by 58%. (The DPP consists of an intensive 16-week healthy lifestyle intervention followed by a maintenance phase, administered via smartphone or computer.)
Dr. Van Name also recommends starting with simple interventions at home and expanding on them over time, especially when working with children. “With kids, we don’t expect a total 180,” she says. “A family can help by figuring out what will motivate a child.”
They might start by exploring ways as a family to get more physical activity or try different-colored foods on the dinner plate, she adds. “If much of the food on your plate is green, that's great. But if it’s all a beige color, it's often a less-healthy meal," Dr. Van Name says. “Managing stress, which can be a roadblock, is also important.”
What if lifestyle changes don’t lead to weight loss?
If adults and children have difficulty changing lifestyle habits themselves, there are options, including a variety of types of weight-loss surgery (which in itself has been shown to reverse type 2 diabetes) and medications.
Some doctors prescribe metformin, a front-line medication for type 2 diabetes, “off-label” for prediabetes (meaning doctors prescribe it for a condition even though the Food and Drug Administration [FDA] hasn’t specifically approved it for that condition). “Metformin is a good tool,” Dr. Anam says, adding that studies have shown the drug can decrease the risk of progression to type 2 diabetes, although to a lesser degree than lifestyle changes.
Meanwhile, Dr. Jastreboff is studying medications to treat obesity. One of those drugs, semaglutide (available by prescription), is FDA-approved for treatment of both diabetes and obesity in adults; for diabetes the brand name is Ozempic™, for obesity the brand name is Wegovy™. It has helped some people shed 15% of their body weight. It’s currently undergoing Phase 3 trials in adolescents.
Another medication is tirzepatide, which the FDA has approved as a treatment for type 2 diabetes. In a study published in the New England Journal of Medicine in June 2022, participants who took tirzepatide once weekly for the treatment of obesity had a substantial and sustained reduction in body weight, says Dr. Jastreboff, who was the study’s principal investigator.
How can we reduce the number of people with prediabetes?
One of the challenges to bringing down prediabetes is identifying who has it, since many people aren’t automatically screened for the condition. In 2021, a U.S. Preventive Services Task Force recommended lowering the initial screening age for prediabetes (and type 2 diabetes) to age 35 for asymptomatic adults who have overweight or obesity. But that doesn’t cover people younger than 35—and a CDC study published in 2019 showed one in five adolescents and one in four young adults up to age 34 were already living with it.
Was the pandemic responsible for the rise in prediabetes cases?
“The COVID-19 pandemic pushed a lot of people who were already on the edge,” says Dr. Anam. While there may have been an increase in prediabetes diagnoses anyway, doctors have been concerned about remote work and school shutdowns leading to sedentary habits and weight gain, all of which can create a foundation for the condition.
For those who had COVID, the treatment itself may have identified a problem. "In some cases, for people who may have had undiagnosed prediabetes or diabetes, the use of high-dose steroids as part of the management for COVID-19 may have sent them over the edge, unmasking persistently high glucose levels consistent with type 2 diabetes,” she says.
Is it really possible to reverse prediabetes?
What’s important to remember is that prediabetes may be reversed, explains Dr. Anam. “I’ve had patients achieve tremendous things,” she says, adding that starting early helps.
Parents may need to talk to a pediatrician when their children are in adolescence—or even before that—and adults should assess their lifestyles while they are still in their 20s or 30s, she adds. "Glucose tolerance worsens with age, so problems that aren’t controlled early may be more difficult later on," she says.
Anyone who is concerned should understand their glucose numbers and check them routinely. “You should know your weight, your blood pressure, and your A1C,” Dr. Anam says. “Keep tabs on your health and take action if you need to.”