More than 95% of people with diabetes have type 2, according to the World Health Organization. The CDC places that figure between 90% and 95% of all cases in the United States. Either way, type 2 diabetes is overwhelmingly the most common form of the disease.
How the Other Types Break Down
Type 1 diabetes accounts for roughly 5% to 10% of cases. It is an autoimmune condition in which the body attacks the cells that produce insulin, and it typically appears in childhood or early adulthood, though it can develop at any age. About 2% of people with diabetes have rarer forms, including types caused by genetic mutations (sometimes called monogenic diabetes), cystic fibrosis-related diabetes, or diabetes triggered by other medical conditions or medications.
There is also a form called latent autoimmune diabetes in adults, which shares features of both type 1 and type 2. It progresses more slowly than type 1 and is sometimes misdiagnosed as type 2 in its early stages. This overlap makes precise counting difficult, but it does not significantly change the overall picture: type 2 dominates the statistics by a wide margin.
Why Type 2 Is So Much More Common
Type 2 diabetes develops when the body becomes less responsive to insulin and eventually cannot produce enough to keep blood sugar in a normal range. The biggest risk factors are carrying excess weight, being physically inactive, and having a family history of diabetes. Unlike type 1, which is driven by an immune system malfunction, type 2 is closely tied to lifestyle and metabolic factors that affect large portions of the population. Rising rates of obesity and sedentary work have pushed type 2 numbers steadily upward for decades.
Who Is Most Affected
Type 2 diabetes does not affect every group equally. In the U.S., the prevalence of diagnosed diabetes among adults varies sharply by race and ethnicity. American Indian and Alaska Native adults have the highest rate at 15.7%, followed by Black non-Hispanic adults at 12.2%, Hispanic adults at 11.8%, and Asian non-Hispanic adults at 9.7%. White non-Hispanic adults have the lowest rate at 7.1%. These disparities reflect a combination of genetic susceptibility, socioeconomic factors, and differences in access to healthcare and healthy food.
Age is another major factor. The percentage of adults with diabetes climbs steeply in older age groups, reaching 28.8% among those 65 and older. This makes sense biologically: insulin resistance tends to worsen over time, and the metabolic effects of weight gain and inactivity accumulate across a lifetime.
Type 2 Is Rising in Young People
Type 2 diabetes was once considered an adult disease. That is no longer the case. Between 2002 and 2018, the rate of new type 2 diagnoses in children and adolescents doubled, going from 9 per 100,000 to 18 per 100,000 per year. That translates to roughly a 5% annual increase in new cases among young people. Rising childhood obesity is the primary driver, and the trend shows no sign of reversing.
Many Cases Go Undiagnosed
A significant number of people with type 2 diabetes don’t know they have it. CDC data from 2021 to 2023 shows that while 11.3% of U.S. adults had a diabetes diagnosis, an additional 4.5% met the laboratory criteria for diabetes but had never been told by a healthcare provider. That means roughly one in four adults with diabetes are walking around undiagnosed. Men are somewhat more likely to be in this group (5.1%) than women (3.9%).
Undiagnosed diabetes is particularly concerning because the condition causes damage to blood vessels, nerves, kidneys, and eyes even when a person feels fine. By the time symptoms become obvious, complications may already be underway. This is a major reason public health agencies recommend routine blood sugar screening for adults over 35 or anyone with risk factors like obesity or a family history.
The Prediabetes Pipeline
Beyond the people already living with diabetes, an enormous number are on the path toward it. An estimated 115.2 million U.S. adults have prediabetes, a condition in which blood sugar levels are elevated but not yet high enough for a diabetes diagnosis. Among adults 65 and older, more than half (52.1%) have prediabetes. Without changes in diet, activity, or body weight, a meaningful fraction of these individuals will progress to type 2 diabetes over the following years. Modest weight loss of 5% to 7% of body weight and regular physical activity have been shown to cut that progression risk substantially.