A new analysis by 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 worldwide who have diabetes are unaware of their condition. The study reviewed data from 2000 to 2023 across 204 countries and included both type 1 and type 2 diabetes, with most undiagnosed cases involving type 2.
Key findings
– About 44% of people with diabetes globally are undiagnosed.
– Young adults have the highest rates of undiagnosed diabetes and face greater long-term complication risks.
– Of those diagnosed, 91% receive some pharmacological treatment, but only about 42% of treated patients achieve optimal blood sugar control.
– 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 (under 20% aware).
U.S. context
The CDC estimates more than 29 million U.S. adults have diagnosed diabetes, while another roughly 8 million are unaware they have the disease — an undiagnosed rate near 20% in the United States.
Health risks and concerns
Researchers warn undiagnosed and poorly managed diabetes can quietly progress to serious complications, including cardiovascular disease, neuropathy, kidney damage, and other microvascular complications. IHME researchers called undiagnosed diabetes a potential “silent epidemic” and urged investments in screening programs, improved access to medications, and wider availability of glucose-monitoring tools.
Expert views
David Cutler, MD, a family medicine physician not involved with the study, said the findings underscore the need to raise awareness and screen more people. Lauryn Stafford, IHME lead author, emphasized that without diagnosis, people won’t receive treatment or lifestyle guidance, increasing risk for complications. Rita Kalyani, MD of the American Diabetes Association, noted that many people are asymptomatic in early stages, reinforcing the importance of screening.
Symptoms and screening
Type 1 diabetes is an autoimmune condition causing insulin deficiency and affects a smaller number of adults; type 2 is a chronic condition involving impaired blood sugar regulation and accounts for the majority of cases. Prediabetes — elevated blood sugar not yet at diabetes levels — affects many more people.
Common warning signs can include:
– Frequent urination
– Excessive thirst
– Increased hunger despite eating
– Extreme fatigue
– Blurry vision
– Slow-healing cuts or bruises
– Unexplained weight loss (type 1)
– Tingling, pain, or numbness in hands/feet (type 2)
Because symptoms may be absent or mild early on, routine screening (for example, an A1c test that reflects average blood sugar over three months) is important, especially for people with risk factors. Stafford noted barriers to screening include limited healthcare access for underinsured or rural populations and differing screening practices for younger adults.
Prevention and treatment
Type 2 diabetes treatment typically emphasizes lifestyle changes: regular physical activity, weight management, and a diet rich in fiber, whole grains, fruits, and vegetables while minimizing sweets, refined carbs, and excess animal fats. Medications such as metformin are commonly used to lower glucose and improve insulin response. Some GLP-1 receptor agonists (for example, Ozempic and Mounjaro) are approved both for weight loss and for treating type 2 diabetes.
Bottom line
Many people globally — and millions in the U.S. — have diabetes without knowing it. Early diagnosis through screening and better access to treatment and monitoring are essential to prevent the long-term, often silent harms of uncontrolled diabetes.
