An estimated 9.5 million people are living with type 1 diabetes worldwide as of 2025. That figure comes from the International Diabetes Federation’s 11th Edition Atlas and represents a 13% increase from the 8.4 million estimated in 2021. Of those 9.5 million, about 1 million are children under 15 and 800,000 are teenagers aged 15 to 19.
Why the Number Keeps Rising
The jump from 8.4 million to 9.5 million in just a few years reflects a combination of factors. Better diagnostic tools and expanded healthcare access in lower-income countries mean more people are being identified. At the same time, incidence rates have been climbing steadily for decades, particularly among children, though researchers still don’t fully understand why. Type 1 diabetes is an autoimmune condition where the body’s immune system destroys the cells in the pancreas that produce insulin. Unlike type 2 diabetes, it isn’t linked to weight or lifestyle, and it can’t be prevented with current medical knowledge.
Most Diagnoses Happen in Adults
Type 1 diabetes is often thought of as a childhood disease, but that picture is outdated. More than half of all new type 1 diagnoses occur in people aged 20 and older. Adult-onset type 1 diabetes is frequently misdiagnosed as type 2, which can delay proper treatment by months or even years. This matters because people with type 1 diabetes need insulin from the point of diagnosis to survive, and the wrong treatment plan can lead to dangerous complications.
Millions Go Undiagnosed
The 9.5 million figure only captures people who have been identified and are receiving some form of care. In many parts of the world, particularly sub-Saharan Africa and parts of South Asia, people develop type 1 diabetes and never receive a diagnosis. The T1D Index, a data platform tracking the global burden of the disease, puts it starkly: for every two people living with type 1 diabetes, a third person is missing, someone who should still be alive but likely died without a diagnosis or access to insulin.
If every person with type 1 diabetes could be promptly diagnosed and treated, an estimated 393,000 additional people could be alive by 2040. The gap between diagnosed and undiagnosed cases is largest in low-income countries, where insulin supply chains are unreliable and basic blood sugar testing may not be available.
Impact on Life Expectancy
Even with proper treatment, type 1 diabetes shortens life expectancy. A 2025 meta-analysis published in Frontiers in Endocrinology found that men with type 1 diabetes live an average of about 65 years, compared to roughly 80 years for men without diabetes. Women with type 1 diabetes average about 68 years, compared to around 84 for women without the condition. That translates to roughly 11 fewer years of life for both men and women.
These averages vary widely by country and by how well someone can manage their blood sugar over a lifetime. In high-income countries with access to insulin pumps, continuous glucose monitors, and regular specialist care, the gap is narrower. In places where even basic insulin is hard to get, a type 1 diagnosis in childhood can still be a death sentence within months.
The Financial Weight of Type 1 Diabetes
Managing type 1 diabetes is expensive. In the United States alone, a study funded by Breakthrough T1D (formerly JDRF) estimated the collective lifetime management cost at $813 billion. That includes insulin, glucose monitoring supplies, regular medical visits, and the cost of treating complications like kidney disease and vision loss. No comparable global figure exists, but the financial burden falls hardest on people in countries without universal healthcare or insurance coverage, where insulin costs can consume a family’s entire income.
How Type 1 Compares to Type 2
Type 1 diabetes accounts for a small fraction of total diabetes cases worldwide. Of the roughly 537 million adults living with diabetes globally, the vast majority have type 2. But the per-person burden of type 1 is arguably higher: it requires lifelong insulin therapy with no exceptions, constant blood sugar monitoring, and carries a greater risk of life-threatening emergencies like diabetic ketoacidosis. People with type 1 diabetes cannot manage their condition through diet or exercise alone, and there is currently no way to reverse or cure it.