Approximately 589 million adults worldwide are living with diabetes, according to the most recent data from the International Diabetes Federation’s 2025 Diabetes Atlas. That works out to about 1 in 9 adults between the ages of 20 and 79. And nearly half of them don’t know they have it.
The Global Numbers in Context
The 589 million figure captures only diagnosed and estimated adult cases. An additional 1.8 million children and adolescents under 20 are living with type 1 diabetes worldwide. When you add the estimated 541 million adults living with prediabetes (blood sugar levels that are elevated but not yet in the diabetes range), well over a billion people globally have some degree of blood sugar dysregulation.
Of those 589 million adults, roughly 43% are undiagnosed. That’s about 252 million people walking around with diabetes who don’t know it. This matters because unmanaged diabetes quietly damages blood vessels, kidneys, nerves, and eyes for years before symptoms become obvious. The gap between actual cases and diagnosed cases is one of the biggest challenges in global health.
Type 1 vs. Type 2 Breakdown
Type 2 diabetes accounts for 96% of all diabetes cases globally. In every single one of the 204 countries and territories tracked by the Global Burden of Disease Study, type 2 made up more than 80% of cases. In 183 of those countries, it exceeded 90%.
Type 2 diabetes develops when the body gradually loses its ability to use insulin effectively, typically over years or decades. It’s closely tied to weight, physical activity levels, diet, and genetics. Type 1 diabetes, by contrast, is an autoimmune condition where the immune system destroys the cells that produce insulin. It usually appears in childhood or adolescence, though it can develop at any age. The 1.8 million children living with type 1 diabetes globally face a lifelong need for insulin, and in lower-income countries, access remains a serious problem. An estimated 30,000 children die each year because their type 1 diabetes goes undiagnosed at onset.
How Fast Diabetes Is Growing
The trajectory is steep. In 2019, the global estimate stood at 463 million adults. By 2024, that number had jumped to 589 million, a 27% increase in just five years. Projections suggest the total will reach roughly 700 million by 2045, a 51% increase from 2019 levels.
Several forces are driving this growth. Populations are aging, and diabetes risk rises sharply with age. Urbanization is changing diets and activity patterns across low- and middle-income countries, where the fastest increases are occurring. Obesity rates continue to climb in nearly every region. And better screening is catching cases that would have gone undetected a decade ago, which paradoxically inflates the numbers even as it improves outcomes for individuals.
Deaths and Health Consequences
Diabetes was the direct cause of 1.6 million deaths in 2021. But that number significantly understates the real toll. An additional 530,000 kidney disease deaths were caused by diabetes that year, and elevated blood sugar contributes to roughly 11% of all cardiovascular deaths globally. Heart attacks, strokes, kidney failure, blindness, and lower-limb amputations are among the most common serious complications.
Perhaps the most striking detail: 47% of diabetes-related deaths occurred in people under 70. This isn’t purely a disease of old age. In many parts of the world, particularly in sub-Saharan Africa and South Asia, diabetes is killing people in their most productive years, often because diagnosis comes too late or treatment isn’t accessible.
The Economic Scale
Global spending on diabetes-related health care reached an estimated $966 billion in 2021, making it one of the most expensive chronic conditions on the planet. That figure is projected to surpass $1 trillion by 2045. These costs include insulin and other medications, hospitalizations for complications, dialysis for kidney failure, and the ongoing monitoring that diabetes demands. In many countries, diabetes-related expenses consume a significant share of the total health budget, crowding out spending on other conditions.
Why the Undiagnosed Number Matters Most
Of all the statistics, the 252 million undiagnosed cases may be the most important. Type 2 diabetes often produces no noticeable symptoms for years. By the time someone experiences increased thirst, frequent urination, or blurry vision, damage to small blood vessels and organs may already be well underway. A simple blood sugar test can detect diabetes early, and catching it sooner dramatically reduces the risk of complications. The gap between how many people have diabetes and how many know they have it represents millions of preventable heart attacks, strokes, and cases of kidney failure every year.