Around 850,000 people in the UK are living with type 2 diabetes without knowing it. Millions more have pre-diabetes — a state where blood sugar is elevated but not yet at diabetic levels, and where the trajectory is still reversible. Here is what you need to know.

Why type 2 diabetes matters — and why early detection does too

Type 2 diabetes is a condition in which the body either does not produce enough insulin, or does not use insulin effectively, leading to persistently elevated blood sugar levels. Over time, high blood sugar causes progressive damage to blood vessels and nerves throughout the body — affecting the heart, kidneys, eyes, and feet.

The insidious nature of type 2 diabetes is that it is largely symptomless in its early stages. By the time many people receive a diagnosis, they have already had elevated blood sugar for years. During that time, silent damage has been accumulating. The average person with type 2 diabetes has been living with the condition for four to seven years before it is detected.

This matters because the earlier the condition is identified, the more that can be done — including, in many cases, reversing it entirely.

Who is at risk?

Type 2 diabetes is not a condition that affects only people who are overweight or sedentary, though these are significant risk factors. The picture is more complex:

Age. The risk of type 2 diabetes increases with age, particularly from 45 onwards. However, rates in younger adults have risen sharply in recent decades.
Weight and body composition. Excess body fat — particularly fat stored around the abdomen — impairs the body's ability to use insulin effectively. A waist circumference above 88cm in women or 102cm in men is associated with significantly higher risk.
Ethnicity. People of South Asian, Black African, African-Caribbean, and Middle Eastern heritage develop type 2 diabetes at higher rates, often at younger ages and lower BMIs, than the white British population. For people from these backgrounds, screening thresholds are adjusted accordingly.
Family history. Having a parent or sibling with type 2 diabetes roughly doubles your risk.
Gestational diabetes. Women who develop diabetes during pregnancy have a significantly elevated lifetime risk of developing type 2 diabetes — as much as seven times higher than the general population.
Pre-diabetes. An HbA1c between 42 and 47 mmol/mol, or a fasting glucose between 6.1 and 6.9 mmol/L, indicates pre-diabetes. Without lifestyle changes, around 5 to 10% of people with pre-diabetes will progress to type 2 diabetes each year.
Polycystic Ovary Syndrome (PCOS). PCOS is associated with insulin resistance, and women with PCOS have a substantially elevated lifetime risk.
Long-term steroid use. Oral corticosteroids can impair insulin sensitivity and cause steroid-induced diabetes, which can persist even after the medication is stopped.

What are the early signs?

Early type 2 diabetes is often symptomless, which is precisely why blood tests are essential. When symptoms do appear, they can be subtle enough to be explained away:

Increased thirst and more frequent urination, particularly at night.
Unexplained fatigue — not the ordinary tiredness of a busy life, but a persistent, heavy exhaustion that does not resolve with rest.
Blurred vision — caused by fluid changes in the lens of the eye as blood sugar fluctuates.
Slow-healing cuts and infections — high blood sugar impairs immune function and the body's ability to repair tissue.
Tingling or numbness in the hands and feet — an early sign of nerve damage (peripheral neuropathy) that warrants prompt investigation.

If you are experiencing any combination of these symptoms — particularly if you have known risk factors — a blood test is straightforward and unambiguous.

How type 2 diabetes is detected

The two key blood tests used to diagnose and screen for type 2 diabetes are:

HbA1c. This measures the percentage of haemoglobin that has glucose attached — effectively a three-month average of blood sugar levels. It is the preferred diagnostic test because it does not require fasting and is less affected by day-to-day variation. An HbA1c of 48 mmol/mol (6.5%) or above on two occasions confirms a diagnosis of diabetes. Between 42 and 47 mmol/mol indicates pre-diabetes.
Fasting glucose. A blood sample taken after at least eight hours without food. A reading of 7.0 mmol/L or above on two occasions is diagnostic. Between 6.1 and 6.9 is impaired fasting glucose (pre-diabetes).

These tests are included in AtWell's routine blood test panels, and form a core part of our health screening packages.

Pre-diabetes: the window of opportunity

Pre-diabetes is not a diagnosis to dismiss. It is a clear signal that the body's blood sugar regulation is under strain — but it is also a window of opportunity, because at this stage, the progression to type 2 diabetes is genuinely reversible.

The evidence for lifestyle intervention in pre-diabetes is compelling. Large clinical trials have shown that moderate weight loss (5 to 7% of body weight) combined with increased physical activity reduces the risk of progression to type 2 diabetes by 58% — significantly more effective than medication alone. The NHS Diabetes Prevention Programme offers structured support for people with pre-diabetes, and private dietetic or lifestyle coaching can accelerate progress.

The key is to act on the finding rather than file it away. A pre-diabetes diagnosis with no follow-up is not a win — it is a missed opportunity.

If you are diagnosed with type 2 diabetes

A diagnosis of type 2 diabetes is not the end of a conversation — it is the beginning of one. For many people, particularly those diagnosed in the early stages, the condition is eminently manageable and in some cases reversible through significant dietary change and weight loss.

Initial management typically involves structured dietary advice (a low-carbohydrate or energy-restricted diet is now well-evidenced), increased physical activity, and regular monitoring of blood sugar and HbA1c. Medication — most commonly metformin — is introduced when lifestyle measures are insufficient or HbA1c remains significantly elevated.

Regular monitoring is also important for picking up complications early: annual eye checks (diabetic retinopathy screening), kidney function tests, foot assessments, and cardiovascular risk review are standard components of ongoing diabetes care.

How AtWell can help

Whether you have never had a blood sugar test and want to know where you stand, or you have received a pre-diabetes result and want a clear plan of action, our health screening service can provide a thorough assessment and a personalised clinical discussion. Our blood test panels include HbA1c and fasting glucose alongside a comprehensive range of other health markers, with results reviewed and explained by a clinician — not simply emailed as a list of numbers.

Acting now, before symptoms develop, is always better than waiting. The biology of pre-diabetes and early type 2 diabetes is forgiving — but only for so long.

"I was only 46 when my HbA1c came back in the pre-diabetic range. I didn't feel unwell at all. Two years on — with help from the team — I've lost weight, my HbA1c is back to normal, and I feel better than I have in years."
-- AtWell patient, Birmingham

Type 2 diabetes: prevention, early detection, and what to do if you're at risk