Roughly 38 million Americans have type 2 diabetes, making it one of the most common chronic conditions in the country. That figure includes both the millions who know they have it and a sizable group who don’t. Type 2 accounts for about 91% of all diagnosed diabetes cases in the U.S., with type 1 making up about 6% and other forms covering the rest.
Total Numbers and What They Include
CDC data from 2021 to 2023 put the overall prevalence of diabetes among U.S. adults at 15.8%. That breaks down into 11.3% with a diagnosis and 4.5% who meet the lab criteria for diabetes but have never been told they have it. When you apply the 91% type 2 share to these figures, the vast majority of those cases are type 2.
On top of that, 115.2 million American adults, more than 2 in 5, have prediabetes. Their blood sugar is elevated but hasn’t crossed the diabetes threshold yet. Eight in 10 people with prediabetes don’t know they have it, which means a massive pool of people are at risk of progressing to type 2 without realizing it.
How Many People Don’t Know They Have It
About 11 million U.S. adults have undiagnosed diabetes. That’s 27.6% of everyone living with the condition. These are people whose fasting blood sugar or A1c levels meet the clinical cutoff, but who have never received a diagnosis from a doctor. Men are more likely to be undiagnosed than women, with age-adjusted rates of 4.9% versus 3.5%.
Undiagnosed diabetes is particularly dangerous because high blood sugar silently damages blood vessels, nerves, kidneys, and eyes over time. By the time symptoms become obvious, complications may already be underway. This is one reason routine blood sugar screening matters, especially for people over 35, those with a family history, or those carrying extra weight around the midsection.
Type 2 Diabetes Is Rising in Young People
Type 2 diabetes used to be called “adult-onset diabetes” because it was nearly unheard of in children. That’s no longer true. In 2002, about 9 out of every 100,000 young people were newly diagnosed with type 2 each year. By 2018, that number had doubled to 18 per 100,000, roughly a 5% annual increase in new cases. Rising rates of childhood obesity are the primary driver, and the trend shows no sign of reversing.
The Financial Weight of the Disease
Diabetes is the most expensive chronic condition in the United States. Between direct medical costs and lost wages and productivity, it costs the country $413 billion a year. People with diabetes spend roughly double what people without it spend on healthcare. Much of that cost comes from managing complications like heart disease, kidney failure, and nerve damage, conditions that are far more common when blood sugar stays elevated for years.
Diabetes as a Cause of Death
Diabetes is currently the 7th leading cause of death in the U.S., responsible for 94,445 deaths in the most recent mortality data from 2024. That number almost certainly undercounts the true toll. Diabetes dramatically raises the risk of heart attack and stroke, which are the first and fifth leading causes of death respectively. When someone with diabetes dies of a heart attack, the death certificate often lists heart disease as the cause, not diabetes, even though elevated blood sugar was a major contributing factor.
Who Is Most Affected
Type 2 diabetes does not affect all groups equally. Risk climbs sharply with age, with the highest rates among adults 65 and older. But age is only part of the picture. American Indian and Alaska Native, Black, and Hispanic adults all develop type 2 diabetes at significantly higher rates than non-Hispanic white adults. Asian Americans also face elevated risk, often at lower body weights than other groups, which can make the condition easier to miss.
These disparities reflect a tangle of factors: genetics, access to affordable healthy food, neighborhood walkability, healthcare access, and the chronic stress that comes with economic disadvantage. Geography matters too. Diabetes rates tend to be highest in the Southeast and parts of Appalachia, regions where poverty rates are higher and access to preventive care is more limited.
Why the Numbers Keep Growing
The U.S. diabetes count has been climbing for decades, driven by rising obesity rates, an aging population, and more sedentary lifestyles. Processed food is cheap and calorie-dense. Many jobs involve sitting for eight or more hours a day. And once someone develops prediabetes, without intervention about 15% to 30% will progress to full type 2 diabetes within five years.
The silver lining is that type 2 diabetes is often preventable or at least delayable. Losing 5% to 7% of body weight and getting 150 minutes of moderate physical activity per week cuts the risk of progression from prediabetes to diabetes by more than half. For the 115 million Americans already in the prediabetes zone, that’s a meaningful window of opportunity, but only if they know their blood sugar numbers in the first place.