Diabetes is extremely common. More than 800 million adults worldwide are living with diabetes, and the global prevalence has doubled in just three decades, rising from 7% to 14% of all adults between 1990 and 2022. In the United States alone, about 40.1 million people have diabetes, roughly 1 in every 8 Americans.
Global Prevalence at a Glance
The scale of diabetes today is staggering compared to even a generation ago. The World Health Organization reported that adult diabetes cases increased four-fold over the past few decades, with the sharpest rises in low- and middle-income countries where access to screening and treatment is limited. The International Diabetes Federation projects the global total will reach 578 million by 2030 and 700 million by 2045 if current trends continue.
Perhaps the most alarming figure is how many people don’t know they have it. Globally, about 42.8% of adults with diabetes are undiagnosed, equating to roughly 252 million people walking around with elevated blood sugar and no awareness of the damage it may be causing to their blood vessels, kidneys, and nerves.
Type 2 Makes Up the Vast Majority
More than 95% of all diabetes cases are type 2, the form linked to insulin resistance that typically develops in adulthood. In type 2 diabetes, the body still produces insulin but can’t use it effectively, and the pancreas gradually struggles to keep up with demand. Risk factors include excess body weight, physical inactivity, and family history.
Type 1 diabetes, where the immune system destroys the insulin-producing cells in the pancreas, accounts for a much smaller share. It’s most often diagnosed in childhood or adolescence and requires insulin from the start. Though type 1 is less common overall, it remains one of the most frequent chronic diseases in children.
Diabetes Rates in the United States
The CDC puts the U.S. total at 40.1 million people with diabetes. Age is the single biggest demographic factor: 28.8% of adults aged 65 and older have diabetes, compared to much lower rates in younger age groups. This partly reflects the cumulative effect of years of insulin resistance, but also the fact that screening becomes more routine later in life.
The financial toll is enormous. The total estimated cost of diagnosed diabetes in the U.S. in 2022 was $412.9 billion. That includes $306.6 billion in direct medical costs (doctor visits, medications, hospitalizations, insulin, supplies) and $106.3 billion in indirect costs like missed work, reduced productivity, and disability.
Prediabetes: The Larger Hidden Problem
Behind the 40 million Americans with diabetes sits an even larger group. An estimated 115.2 million U.S. adults, more than 2 in 5, have prediabetes. That means their blood sugar is elevated above normal but hasn’t crossed the threshold for a diabetes diagnosis. Without changes in diet, activity, or weight, roughly 15% to 30% of people with prediabetes will develop type 2 diabetes within five years.
The most concerning part: 8 in 10 adults with prediabetes don’t know they have it. Prediabetes causes no obvious symptoms, so the only way to catch it is through a blood test. If you have risk factors like being overweight, having a family history of diabetes, or being over 45, a simple fasting blood sugar or A1C test can reveal whether you’re in this range.
Rising Rates in Children and Teens
Diabetes is no longer just an adult problem. CDC data tracking new cases among people under 20 found that both type 1 and type 2 diagnoses increased between 2002 and 2018. New type 1 cases rose from 20 per 100,000 young people to 22 per 100,000, a roughly 2% annual increase. Type 2 cases in the same age group doubled, going from 9 per 100,000 to 18 per 100,000, a 5% annual increase.
Type 1 was typically diagnosed around age 10 in girls and age 12 in boys, while type 2 diagnoses clustered around age 16 for both sexes. The annual increase in new cases was highest among Asian/Pacific Islander, Hispanic, and non-Hispanic Black youth, pointing to disparities that likely involve both genetic susceptibility and unequal access to healthy food, safe places to exercise, and preventive healthcare.
Gestational Diabetes During Pregnancy
Gestational diabetes develops during pregnancy in women who didn’t previously have diabetes. Global prevalence ranges widely, from about 1% to 28% of pregnancies depending on the population studied. In the U.S., the rate sits between 5% and 6%. Southeast Asia has the highest rates globally.
Gestational diabetes typically resolves after delivery, but it signals a significantly higher risk of developing type 2 diabetes later in life. Women diagnosed with gestational diabetes are often advised to get screened for type 2 diabetes every one to three years after giving birth.
Why the Numbers Keep Climbing
Several forces are driving the global surge. Rising rates of obesity are the most direct cause, since excess body fat, particularly around the abdomen, increases insulin resistance. Urbanization has shifted diets toward processed, calorie-dense foods while reducing physical activity. Populations are also aging, and diabetes risk climbs with every decade of life.
Better screening may also play a role in the rising numbers. As more countries adopt routine blood sugar testing, previously undiagnosed cases get counted. But the four-fold increase in global cases over recent decades far exceeds what improved detection alone could explain. The underlying biology of the epidemic is real: more people are developing insulin resistance, and they’re developing it younger.