Diabetes Doesn't Always Announce Itself

Why millions of people are living with diabetes without knowing it, and why early detection is about more than awareness.

What if you had diabetes and didn't know?

You might go to work, exercise, see your friends and feel completely fine. You would have little reason to think about diabetes.

Yet type 2 diabetes can develop for years before someone notices anything unusual.

That is part of what makes undiagnosed diabetes so concerning. Some people experience symptoms, but others do not. In some cases, complications are already developing before the condition is identified.

Feeling well is not a reliable way to rule out diabetes.

Millions of people don't know they have diabetes

According to the International Diabetes Federation's 2025 Diabetes Atlas, an estimated 589 million adults aged 20–79 were living with diabetes worldwide in 2024. Of those, approximately 252 million, around 43%, were undiagnosed.

But what does it mean to be undiagnosed? For some people, it means having no symptoms and no reason to ask for a test. For others, the barriers are practical. Getting to a clinic might require money for transport, time away from work or a long journey to a facility that may not even have the supplies needed.

The reasons differ, but the result is the same. People are living with a condition they have not had the opportunity to identify or manage.

Why is diabetes so easy to miss?

Type 2 diabetes often develops over time. Some people notice increased thirst, frequent urination, fatigue, blurred vision or unexplained weight loss. Others experience symptoms so mild that they are easily attributed to stress, ageing or everyday exhaustion. Some experience no noticeable symptoms at all.

This is one reason why relying on symptoms alone is not enough to identify everyone living with diabetes.

Type 1 diabetes can develop rapidly and requires insulin treatment. Vomiting, abdominal pain and deep or rapid breathing may be signs of diabetic ketoacidosis (DKA), a life-threatening emergency that requires immediate medical attention. DKA can also occur in people with type 2 diabetes.

For people at increased risk of type 2 diabetes, appropriate testing can help identify the condition before symptoms or complications become apparent.

Why does diagnosis depend so much on where you live?

A 2026 analysis based on the IDF Diabetes Atlas estimated that approximately 72.6% of adults living with diabetes in the IDF Africa Region were undiagnosed, compared with around 29.1% in North America and the Caribbean. These regional estimates mask substantial differences within countries and communities.

The gap is visible across income groups too. The 2026 analysis estimated that 58.7% of adults with diabetes in low-income countries were undiagnosed, compared with 28.9% in high-income countries. That does not tell us the cost of a test in any particular clinic, but it shows why early detection cannot be discussed without considering resources and health-system capacity.

And diagnosis is only one part of the problem. What happens when someone gets a result but cannot afford their medication or return for follow-up care?

What should early action look like?

The theme of World Diabetes Day 2026–2027 is Early Action on Diabetes.

Early action can mean understanding your individual risk, seeking medical advice when symptoms appear, receiving appropriate screening or diagnostic testing, and obtaining timely treatment and follow-up care. For people at increased risk of type 2 diabetes, early support can also help prevent or delay its development.

We think awareness campaigns need to go further. We can encourage people to recognise symptoms and understand their risk, but health systems must also make testing affordable and accessible. And when someone is diagnosed, they need a realistic way to get treatment.

What can you do?

If you have persistent thirst, frequent urination, unusual tiredness, blurred vision or unexplained weight loss, speak to a healthcare professional.

Even if you feel well, ask a healthcare professional whether diabetes testing makes sense for you. Risk factors for type 2 diabetes include increasing age, having a parent or sibling with the condition, previous gestational diabetes, high blood pressure, and living with overweight or obesity, particularly excess weight around the waist. Risk also differs between populations. Diabetes UK advises people from Black African, African Caribbean, Chinese and South Asian backgrounds to consider their risk from a younger age. These are population-level patterns, not a diagnosis or a judgement about any individual.

Depending on your circumstances, a healthcare professional may recommend HbA1c, fasting plasma glucose or another appropriate diagnostic test. Online risk questionnaires can help identify whether further assessment may be useful, but they cannot diagnose diabetes.

If symptoms develop rapidly, especially alongside vomiting, abdominal pain or deep or rapid breathing, seek urgent medical attention.

What happens after the awareness campaign?

World Diabetes Day puts diabetes in the spotlight each November. The real test comes afterwards, when someone needs an appointment, a diagnosis or continuing care.

Can someone who suspects they have diabetes get a timely, affordable test? If the result is positive, is treatment and follow-up care actually available?

We should measure progress by more than the reach of an awareness campaign. Early detection matters when it leads to care people can actually access.