Type 1 diabetes is a chronic autoimmune condition where the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. Insulin is a hormone that allows blood sugar (glucose) to enter cells for energy. Without enough insulin, glucose builds up in the bloodstream, leading to high blood sugar levels. Individuals with Type 1 diabetes require daily insulin injections to manage their blood glucose and sustain life.
How Common is Type 1 Diabetes?
Type 1 diabetes affects millions globally, with its prevalence increasing annually. In 2021, an estimated 8.4 million people worldwide lived with Type 1 diabetes, a number projected to rise to between 13.5 and 17.4 million by 2040. This makes it one of the fastest-growing noncommunicable chronic health conditions globally.
In the United States, approximately 198,000 children and adolescents under 20 years old, and about 1.3 million adults over 20, were living with Type 1 diabetes in 2024. Globally, 1.8 million children and adolescents and 7.3 million adults live with the condition. New cases are also increasing; roughly 20,000 U.S. youth and 32,000 U.S. adults were diagnosed in 2024.
The global incidence for youth under 20 was about 219,000 new diagnoses in 2024, with adults seeing approximately 284,000 new cases worldwide. While Type 1 diabetes often develops in children and young adults, it can appear at any age, and over half of new diagnoses are in individuals 20 years or older.
Type 1’s Share of Diabetes Cases
When considering all diagnosed cases of diabetes, Type 1 diabetes accounts for a smaller but significant proportion. In 2016, Type 1 diabetes constituted approximately 5.8% of all diagnosed diabetes cases in U.S. adults, while Type 2 diabetes made up about 90.9%. Other less common forms of diabetes accounted for the remaining cases. Globally, Type 1 diabetes represents around 5% to 10% of all diabetes cases.
This distinction is important because Type 1 and Type 2 diabetes differ in their causes, progression, and management strategies. In contrast, Type 2 diabetes typically involves insulin resistance, where the body does not use insulin effectively, or the pancreas does not produce enough of it.
Understanding these percentages helps public health officials and healthcare providers allocate resources and develop targeted education and management programs. For example, because Type 2 diabetes is far more prevalent, overall diabetes surveillance data often reflect trends primarily associated with Type 2 diabetes. Recognizing the specific proportion of Type 1 diabetes ensures that its unique challenges and needs are addressed within the broader context of diabetes care.