A new analysis from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, published Sept. 8 in The Lancet Diabetes & Endocrinology, estimates that about 44% of people ages 15 and older with diabetes worldwide are unaware of their condition. The review covered data from 2000 to 2023 across 204 countries and included both type 1 and type 2 diabetes, with most undiagnosed cases being type 2.
Key findings
– Roughly 44% of people with diabetes globally are undiagnosed.
– Young adults have the highest rates of undiagnosed diabetes, placing them at greater risk for long-term complications.
– Of those diagnosed, 91% receive some pharmacologic treatment, but only about 42% of treated patients reach recommended blood sugar targets.
– Regional differences: high-income North America has the highest diagnosis rates; the high-income Asia Pacific region has the highest treatment rates; Southern Latin America has the best rates of optimal control; central sub-Saharan Africa has the lowest diagnosis rates (fewer than 20% aware).
U.S. context
The CDC estimates more than 29 million U.S. adults have diagnosed diabetes, and roughly 8 million more are unaware they have the disease — an undiagnosed rate near 20% in the United States.
Health risks and concerns
Researchers warn that undiagnosed or poorly managed diabetes can progress quietly to serious complications, including cardiovascular disease, neuropathy, kidney damage, and other microvascular harms. IHME researchers described undiagnosed diabetes as a potential “silent epidemic” and urged investments in screening programs, better access to medications, and wider availability of glucose-monitoring tools.
Expert perspectives
Clinicians and study authors emphasized the importance of screening and awareness. David Cutler, MD, a family physician not involved in the study, said the findings highlight the need to screen more people. IHME lead author Lauryn Stafford noted that without diagnosis, people won’t receive treatment or lifestyle guidance, increasing their risk of complications. Rita Kalyani, MD, of the American Diabetes Association, pointed out that many people are asymptomatic in early stages, reinforcing the need for routine screening.
Symptoms and screening
Type 1 diabetes is an autoimmune condition that causes insulin deficiency and affects fewer adults; type 2 is far more common and involves impaired blood sugar regulation. Prediabetes — elevated blood sugar that has not yet reached diabetes thresholds — is also widespread.
Common warning signs may include:
– Frequent urination
– Excessive thirst
– Increased hunger despite eating
– Extreme fatigue
– Blurry vision
– Slow-healing cuts or bruises
– Unexplained weight loss (more typical of type 1)
– Tingling, pain, or numbness in hands or feet (common with type 2)
Because symptoms can be absent or mild early on, routine screening is important, especially for people with risk factors (family history, overweight, sedentary lifestyle, certain ethnic groups, or older age). A1c testing, which reflects average blood sugar over about three months, is commonly used. Barriers to screening include limited healthcare access for underinsured or rural populations and inconsistent screening practices for younger adults.
Prevention and treatment
Type 2 diabetes prevention and treatment emphasize lifestyle measures: regular physical activity, weight management, and a diet higher in fiber, whole grains, fruits, and vegetables while limiting sweets, refined carbs, and excess animal fats. Metformin remains a common first-line medication to lower glucose and improve insulin response. Several GLP-1 receptor agonists (for example, Ozempic and Mounjaro) are approved for treating type 2 diabetes and some are also used for weight loss.
Bottom line
Millions of people worldwide — and millions in the U.S. — have diabetes without knowing it. Early diagnosis through routine screening, improved access to treatment, and better monitoring are essential to prevent the long-term, often silent harms of uncontrolled diabetes.
