About 589 million adults worldwide are living with diabetes, representing just over 11% of the global adult population. In the United States alone, 40.1 million people have diabetes, roughly 1 in 8 adults. These numbers have been climbing steadily for decades, and projections suggest they will continue to rise.
Global Numbers at a Glance
The International Diabetes Federation’s most recent estimates, published in 2025, put the global count at 589 million adults with diabetes as of 2024. That 11.1% prevalence rate is up from 10.5% (536.6 million people) in 2021. By 2045, the number is projected to reach 783 million, or about 12.2% of adults worldwide.
Diabetes is also a major cause of death globally. In 2021, it directly caused 1.6 million deaths, and nearly half of those deaths occurred in people under 70. The toll extends further when you count related conditions: diabetes contributed to an additional 530,000 kidney disease deaths that year and is responsible for roughly 11% of all cardiovascular deaths.
Diabetes in the United States
The CDC reports that 40.1 million Americans are living with diabetes. Of those, 29.1 million have been formally diagnosed. The remaining 11 million don’t know they have it yet, meaning more than 1 in 4 adults with diabetes are undiagnosed. That gap matters because uncontrolled blood sugar silently damages blood vessels, nerves, kidneys, and eyes long before symptoms become obvious.
Beyond those 40 million, another 115.2 million American adults have prediabetes, a condition where blood sugar is elevated but not yet high enough for a diabetes diagnosis. That’s more than 2 in 5 adults. Prediabetes significantly raises the risk of progressing to full diabetes, but it can often be reversed with changes in diet, physical activity, and weight.
Type 1 vs. Type 2
The vast majority of diabetes cases, between 90% and 95%, are type 2. In type 2 diabetes, the body still produces insulin but can’t use it efficiently. Over time, the pancreas can’t keep up with demand, and blood sugar stays elevated. Risk factors include excess weight, physical inactivity, family history, and age.
Type 1 diabetes accounts for the remaining 5% to 10% of cases. It’s an autoimmune condition where the immune system destroys the cells that produce insulin. Type 1 typically appears in childhood or adolescence, though it can develop at any age. Unlike type 2, it isn’t linked to lifestyle factors and always requires insulin therapy.
Age Makes a Big Difference
Diabetes risk rises sharply with age. Among American adults 65 and older, 28.8% have diabetes, compared to much lower rates in younger age groups. New diagnoses also peak in middle age and beyond, with incidence rates notably higher among adults 45 to 64 and those over 65 compared to adults 18 to 44.
Prediabetes follows the same pattern. About 36% of adults aged 18 to 44 have prediabetes, climbing to nearly 49% among those 45 to 64 and topping 52% in adults 65 and older. In other words, more than half of older Americans have blood sugar levels heading in the wrong direction, even if they haven’t crossed the diabetes threshold.
The Economic Burden
Diabetes costs the U.S. an estimated $412.9 billion per year. About $306.6 billion of that goes to direct medical spending: hospital visits, medications, insulin, monitoring supplies, and treatment for complications like kidney disease and nerve damage. The remaining $106.3 billion reflects indirect costs, including missed work, reduced productivity, chronic disability, and premature death. People with diagnosed diabetes spend roughly 2.6 times more on healthcare than they would without the condition.
Why So Many Cases Go Undetected
Type 2 diabetes develops gradually. Blood sugar can be dangerously high for years without producing symptoms that feel urgent. Early signs like increased thirst, frequent urination, fatigue, and blurred vision are easy to dismiss or attribute to aging, stress, or poor sleep. That’s why 11 million Americans are walking around with undiagnosed diabetes.
Simple blood tests can catch it. A fasting blood sugar test or a test that measures average blood sugar over the past two to three months can identify both diabetes and prediabetes. Screening is especially important if you’re over 45, carry extra weight around your midsection, have a family history of diabetes, or have been told your blood sugar is borderline in the past. Catching diabetes early, or catching prediabetes before it progresses, dramatically changes the outlook for long-term health.