About 40.1 million people in the United States have diabetes, which works out to roughly 1 in every 8 Americans. That figure, from the CDC’s most recent national data, includes both diagnosed and undiagnosed cases. Of those 40.1 million, approximately 29.1 million have been formally diagnosed, while an estimated 11 million adults are living with diabetes and don’t yet know it.
Diagnosed vs. Undiagnosed Cases
The gap between diagnosed and undiagnosed diabetes is striking. About 27.6% of U.S. adults with diabetes, more than 1 in 4, have not been diagnosed. These individuals are walking around with elevated blood sugar that’s silently damaging blood vessels, kidneys, and nerves. Undiagnosed diabetes is particularly dangerous because without treatment, the risk of heart disease, vision loss, and kidney failure climbs steadily over time.
Diabetes is typically caught through routine blood work during a checkup, which is one reason people without regular access to healthcare are more likely to fall into the undiagnosed group. A simple blood sugar test or an A1C test (which measures average blood sugar over the past two to three months) is all it takes to identify the condition.
Type 1 vs. Type 2 Breakdown
The vast majority of diabetes cases in the U.S. are type 2. Based on CDC analysis, about 91% of diagnosed cases are type 2, while roughly 6% are type 1. The remaining 3% are other forms, including gestational diabetes and rarer genetic types. In real numbers, that translates to about 1.3 million adults with type 1 diabetes and over 21 million with type 2, though those figures have likely grown alongside the overall increase in total cases.
The distinction matters because these are fundamentally different diseases. Type 1 is an autoimmune condition where the body destroys its own insulin-producing cells, and it typically appears in childhood or young adulthood. Type 2 develops when the body gradually becomes resistant to insulin, usually later in life and often in connection with excess weight, inactivity, and genetics.
Diabetes Rates by Age
Diabetes becomes dramatically more common with age. Among adults 65 and older, 28.8% have the condition, nearly 1 in 3. That’s partly because type 2 diabetes takes years to develop and partly because aging itself reduces the body’s ability to manage blood sugar effectively.
Younger Americans are not immune, though, and trends among children and teenagers are concerning. Between 2002 and 2018, new cases of type 1 diabetes in people under 20 rose about 2% per year. New cases of type 2 diabetes in the same age group climbed even faster, roughly 5% per year, with the rate doubling from 9 to 18 new cases per 100,000 young people annually. Type 2 diabetes in children was once rare enough to be called “adult-onset diabetes.” That term is now outdated.
Where Diabetes Hits Hardest
Diabetes is not evenly distributed across the country. Counties with the highest diagnosed diabetes rates are concentrated in the Southeast, a pattern that tracks closely with higher rates of obesity, poverty, and limited access to healthcare in that region. States like Mississippi, West Virginia, and Alabama consistently report some of the highest prevalence rates in the nation.
Health Consequences
Diabetes is a leading driver of several other serious conditions. About 1 in 3 people with diabetes develop kidney disease, making it the single largest cause of kidney failure in the U.S. Diabetes also significantly raises the risk of heart attack, stroke, nerve damage in the feet and hands, and vision problems that can progress to blindness. These complications tend to develop gradually over years of poorly controlled blood sugar, which is why early diagnosis and consistent management make such a large difference in long-term outcomes.
The Economic Toll
Diabetes costs the U.S. an estimated $412.9 billion per year. Of that total, $306.6 billion goes toward direct medical spending: hospital visits, medications, insulin, doctor appointments, and treating complications. The remaining $106.3 billion reflects indirect costs like missed workdays, reduced productivity, unemployment from diabetes-related disability, and premature death. People with diagnosed diabetes spend roughly 2.6 times more on healthcare than they would without the condition.
Where the Numbers Are Headed
The trajectory is not encouraging. CDC projections estimate that as many as 1 in 3 U.S. adults could have diabetes by 2050 if current trends continue. That projection accounts for two converging factors: the rate of new diagnoses keeps climbing, and people with diabetes are living longer thanks to better treatments, which adds to the total number of people living with the disease at any given time. Even the most conservative version of that forecast puts the future rate at 1 in 5 adults, still a substantial increase from today’s 1 in 8.