About 15.8% of American adults have diabetes, which translates to roughly 40.1 million people, or 1 in every 8. The vast majority of those cases are type 2. On top of that, more than 1 in 4 adults with diabetes don’t know they have it, meaning millions are walking around with elevated blood sugar and no diagnosis.
The Full Picture: Diagnosed and Undiagnosed
National survey data from 2021 to 2023 breaks the total into two groups. About 11.3% of U.S. adults have been diagnosed with diabetes by a healthcare provider. Another 4.5% meet the diagnostic criteria (based on blood sugar or A1C levels) but have never been told they have it. Combined, that’s the 15.8% figure.
Men are slightly more likely to be undiagnosed than women: 5.1% versus 3.9%. That gap matters because undiagnosed diabetes means years of uncontrolled blood sugar silently damaging blood vessels, kidneys, and nerves before anyone intervenes.
Who Is Most Affected
Diabetes does not hit every group equally. Among U.S. adults from 2021 to 2023, the rates of diagnosed diabetes break down by race and ethnicity like this:
- Black, non-Hispanic adults: 12.2%
- Hispanic adults: 11.8%
- Asian, non-Hispanic adults: 9.7%
- White, non-Hispanic adults: 7.1%
Black and Hispanic adults are diagnosed at roughly 1.5 to 1.7 times the rate of white adults. These disparities reflect a mix of factors: differences in access to preventive care, rates of food insecurity, neighborhood environments that make physical activity harder, and in some cases, genetic predisposition. Age is also a powerful driver. Diabetes prevalence climbs sharply after 45 and is highest among adults 65 and older.
Prediabetes: The Much Larger Group
Beyond the 40 million Americans with diabetes, another 115.2 million adults have prediabetes. That’s more than 2 in 5 American adults. Prediabetes means blood sugar is elevated above normal but hasn’t crossed the threshold into diabetes. Specifically, it’s defined as an A1C between 5.7% and 6.4%, compared to 6.5% or higher for diabetes.
Most people with prediabetes don’t know it either, because it rarely causes symptoms. Without lifestyle changes, roughly 15% to 30% of people with prediabetes will develop type 2 diabetes within five years. When you combine people with diabetes and prediabetes, more than half of all American adults have some degree of blood sugar dysregulation.
Rising Rates in Young People
Type 2 diabetes was once called “adult-onset diabetes” for a reason. That label no longer fits. In 2002, about 9 out of every 100,000 young people were newly diagnosed with type 2 diabetes each year. By 2018, that number doubled to 18 per 100,000, a pace of roughly 5% more new cases every year. The typical age at diagnosis for young people is around 16.
This trend tracks closely with rising childhood obesity rates and more sedentary lifestyles. Type 2 diabetes diagnosed in adolescence tends to progress faster and respond less well to treatment than when it develops in middle age, which makes the trend especially concerning for long-term health outcomes.
Health Complications Tied to Diabetes
High blood sugar over time damages small blood vessels throughout the body. The organs most vulnerable are the kidneys, eyes, heart, and nerves in the feet and hands. About 1 in 3 adults with diabetes develops chronic kidney disease, making diabetes the leading cause of kidney failure in the United States. Heart disease and stroke risk roughly double with a diabetes diagnosis. Nerve damage in the feet can lead to infections and, in severe cases, amputations.
Many of these complications develop gradually over years, which is why the millions of undiagnosed cases are so problematic. By the time someone learns they have diabetes through a complication like blurred vision or numbness in their feet, significant damage may already be done.
The Economic Weight
Diabetes is the most expensive chronic condition in the country. The total annual cost reaches $413 billion: $307 billion in direct medical spending and another $106 billion in lost productivity from disability, missed work, and premature death. People with diabetes spend roughly 2.3 times more on healthcare than people without it. Those costs include medications, routine monitoring, and the treatment of complications like dialysis or cardiovascular procedures.
Where the Numbers Are Headed
CDC modeling projects that total diabetes prevalence among U.S. adults will rise from about 14% in 2010 to somewhere between 21% and 33% by 2050, depending on how incidence and mortality trends play out. A middle-ground estimate puts it at 25% to 28%. That would mean roughly 1 in 4 American adults living with diabetes within the next few decades. The trajectory is driven by an aging population, continued high rates of obesity, and the growing number of young people developing the disease earlier in life.