Diabetes and Prediabetes by the Numbers
Diabetes and prediabetes by the numbers, including the large share of people who have them without knowing.
December 15, 2025 · By The Editors, Healing Stories Network · 2 min read
Diabetes is often described as one of the defining health challenges of our time, and the statistics explain why. This post looks at how common diabetes and prediabetes have become, and at the striking number of people who have them without knowing.
This is a data companion piece, not medical advice. The figures describe populations and are approximate; any concern about your own blood sugar belongs with a clinician and a simple test.
A global picture
International diabetes bodies estimate that around one in nine adults worldwide are living with diabetes, a figure that has climbed steadily for decades. Strikingly, roughly half of adults with diabetes are thought to be undiagnosed.
Type 1, type 2, and gestational
The figures above mostly reflect type 2 diabetes, which accounts for the large majority of cases and is linked to factors like weight, activity, and age, though genetics matters too. Type 1 diabetes, an autoimmune condition in which the body stops producing insulin, is far less common and is not caused by lifestyle. Gestational diabetes, a third form, arises during pregnancy and usually resolves after birth. They are distinct conditions that share the single feature of raised blood sugar.
The awareness gap
In the United States, the contrast between diagnosed disease, the much larger pool of prediabetes, and how little of it is recognised is one of the most important pictures in public health.
Why it is rising
The global climb tracks with ageing populations, urbanisation, and changes in diet and daily activity. Some regions have seen especially steep increases as these shifts arrive quickly. The encouraging counterpoint is that type 2 diabetes and prediabetes often respond to changes made early, and the range of treatments has widened considerably in recent years.
Why the numbers matter
Prediabetes and early type 2 diabetes often carry no obvious symptoms, which is why screening matters and why the undiagnosed share is so high. The encouraging side is that early awareness opens the door to changes and treatments that can alter the course. The figures are estimates, updated as testing and reporting improve.
Left unmanaged over years, diabetes can affect the eyes, kidneys, nerves, and heart, which is the real reason the undiagnosed share carries weight. None of this is cause for alarm over a single reading, but it is a strong argument for the simple blood tests that catch raised sugar early, when there is the most room to act.
For the lived side, see our companion pieces on living with type 2 diabetes, SGLT2 inhibitors, and diabetic neuropathy, or browse our Diabetes & Blood Sugar collection.
About these figures: The statistics here are approximate and draw on international diabetes federation estimates and national health surveys. They are revised regularly and vary by country and definition, so treat them as a sense of scale and consult the original sources for current numbers. This article is general information, not medical advice.
This article is a companion, not medical advice. Questions about your own blood sugar belong with a qualified clinician.
The Reading Room publishes personal stories and editorial notes from our press. Everything here is companion reading — never medical advice, diagnosis, or treatment. For guidance about your own health, please speak with a qualified clinician.