Recent data analysis published in The Lancet shows that 44% of people with diabetes – aged 15 and older – are undiagnosed and don’t even know they have it, reports CNN.
The study examined data from 204 countries and territories from 2000 to 2023 in a systematic review of published literature and surveys. The findings at the global level are for people 15 and older.
“The majority of people with diabetes on whom we report in the study have type 2 diabetes,” said Lauryn Stafford, lead author of the study.
Around one in nine adults live with diabetes worldwide, according to the International Diabetes Foundation. In the United States, 11.6% of American have diabetes, show 2021 data from the American Diabetes Association.
“We found that 56% of people with diabetes are aware they have the condition,” said Stafford, a researcher for the Institute for Health Metrics and Evaluation.
“Globally, there’s a lot of variation geographically, and also by age. So, generally, higher-income countries were doing better at diagnosing people than low- and middle-income countries.”
Younger people don’t know they have diabetes
People under 35 were much less likely to be diagnosed than people middle aged or older. “Just 20% of young diabetics were aware of their condition,” Stafford said.
Routine screenings aren’t promoted as much for young adults as for older adults, and some larger organisations, like the American Diabetes Association, suggest annual routine screenings for those aged 35 and older.
“You can survive with elevated glucose levels for many, many years,” Stafford said. “People end up getting diagnosed only at the point where they have complications, which are more common in older adults.”
Depending on how long a person has had diabetes before it’s discovered, the health impacts may vary.
“Early diagnosis is important because it allows for timely management to prevent or delay long-term complications like heart disease, kidney failure, nerve damage, and vision loss,” said Dr Rita Kalyani, Chief Scientific and Medical Officer at the American Diabetes Association. She was not involved in the study.
Around one-third of adults are diagnosed with diabetes later than their earliest symptom, according to a 2018 study.
Symptoms to watch for
“Symptoms of diabetes include increased thirst or hunger, frequent urination, blurry vision, unexpected weight loss and fatigue, but in the early stages, most people with diabetes are asymptomatic, which highlights the importance of screening and diagnosis,” said Kalyani, a Professor of Medicine in the division of Endocrinology, Diabetes and Metabolism at Johns Hopkins University.
Globally, in 2023, about 40% of people with treated diabetes were getting optimal results and lowering their blood sugar, said Stafford. That’s why it’s important that future efforts focus on ensuring that more people receive and follow proper treatment post-diagnosis.
That only four in 10 patients were seeing optimal results was surprising, as several well-established treatments, including insulin, Metformin and other drugs like GLP-1s, are available.
People with diabetes likely also have other health issues, such as hypertension or chronic kidney disease, which can make treatment complex, Stafford added.
“I think, ultimately, that if we can also focus more on the risk factors for developing diabetes – preventing people from needing to be diagnosed in the first place – that is critical,” she added.
Study details
Global, regional, and national cascades of diabetes care, 2000–23: a systematic review and modelling analysis using findings from the Global Burden of Disease Study
Lauryn Stafford, Anna Gage, Yvonne Yiru Xu et al.
Published in The Lancet on 8 September 2025
Summary
Background
Diabetes is a serious global health challenge, with a rising prevalence and substantial effect on disability and mortality worldwide. Despite medical advancements, gaps in the cascade of diabetes care—comprising diagnosis, treatment, and glycaemic management—persist, hindering effective management. We aimed to comprehensively assess the state of the diabetes cascade of care globally, identifying areas of strength and needs for improvement in diabetes management.
Methods
Using data and methods from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), this modelling analysis spanned the years 2000 to 2023 and covered 204 countries and territories. We systematically reviewed cross-sectional surveys that are representative of the general population and the published and grey literature to estimate the proportion of people with diabetes who are undiagnosed, diagnosed but untreated, receiving treatment with suboptimal glycaemic concentrations, and receiving treatment with optimal glycaemic concentrations. Treatment was defined as current use of insulin or other hypoglycaemic medication. We separately modelled these quantities by location, year, age, and sex using DisMod-MR 2.1, a hierarchical Bayesian meta-regression modelling tool, then scaled the estimates so that they sum to 100% of people living with diabetes in each stratum. Using GBD 2023 estimates of the number of people with diabetes, we calculated the diabetes cascade of care: proportion of people diagnosed among those with diabetes, proportion of people receiving treatment among those with diagnosed diabetes, and proportion of people with optimal glycaemic concentrations among those receiving treatment for diabetes across all strata.
Findings
In 2023, an estimated 55·8% (95% UI 49·3–62·3) of people with diabetes aged 15 years and older were diagnosed with diabetes globally. The proportion of people with diagnosed diabetes who were on treatment was 91·4% (88·0–94·2), and the proportion of people on diabetes treatment with optimal glycaemic concentrations was 41·6% (35·7–48·5). Among all people with diabetes, the proportion with optimal glycaemic concentrations on treatment was 21·2% (17·4–25·6) in 2023 globally. Substantial regional differences were observed, with the highest rates of diagnosis in high-income North America, the highest rates of treatment among those with diagnosed diabetes in high-income Asia Pacific, and the highest rates of optimal glycaemic concentrations among those receiving treatment for diabetes in southern Latin America. Between 2000 and 2023, globally, the proportion of people diagnosed with diabetes increased by 8·3 (6·6–10·0) percentage points, and the proportion of people receiving treatment among those diagnosed increased by 7·2 (5·7–8·8) percentage points. The proportion of people receiving treatment who had optimal glycaemic concentrations increased by 1·3 (0·8–1·8) percentage points.
Interpretation
Despite improvements over the past two decades, under-diagnosis and suboptimal glycaemic management of diabetes remain major challenges globally, particularly in low-income and middle-income countries. These findings highlight the urgent need for enhanced strategies and capacity building to improve the detection, treatment, and management of diabetes worldwide. Targeted interventions to bolster health-care systems' capacity to effectively diagnose and manage diabetes could lead to better health outcomes and reduce the burden of this growing disease.
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