What is type 2 diabetes?
Type 2 diabetes is a long-term condition where the level of sugar (glucose) in your blood becomes too high. It happens because the body either does not produce enough insulin, or the insulin it produces does not work properly — a state known as insulin resistance. Insulin is the hormone that allows glucose to move from your bloodstream into your cells to be used for energy.
Over time, persistently high blood sugar can damage blood vessels and nerves, raising the risk of complications affecting the heart, eyes, kidneys and feet. The good news is that type 2 diabetes can often be prevented, delayed or well managed, and many people lead full, healthy lives by keeping their blood sugar within a healthy range.
Symptoms of type 2 diabetes
Type 2 diabetes can develop slowly, and some people have no obvious symptoms for years. When symptoms do appear, they are often mild and easy to overlook. Common signs include:
- •Feeling very thirsty and drinking more than usual
- •Passing urine more often, especially at night
- •Feeling unusually tired
- •Unintentional weight loss
- •Blurred vision
- •Cuts or wounds that heal slowly
- •Frequent infections, such as thrush
- •Tingling or numbness in the hands or feet
What causes type 2 diabetes?
Type 2 diabetes develops when the body becomes resistant to insulin or cannot make enough of it. The exact cause is not fully understood, but a combination of genetic and lifestyle factors is involved. Carrying excess weight, particularly around the abdomen, is one of the strongest risk factors, as is physical inactivity.
Your risk is also higher if you have a close family member with type 2 diabetes, are over 40, have had high blood sugar in pregnancy (gestational diabetes), or belong to certain ethnic groups, including people of South Asian, African, African-Caribbean and Middle Eastern descent, who can develop it at a younger age and lower weight.
How is it diagnosed?
Type 2 diabetes is diagnosed with blood tests that measure your blood sugar. The HbA1c test reflects your average blood sugar over the past two to three months, and a result of 6.5% (48 mmol/mol) or above usually indicates diabetes. A fasting blood glucose test or an oral glucose tolerance test may also be used. Doctors typically confirm the diagnosis with repeat testing.
Many people are diagnosed during routine check-ups before symptoms appear. There is also an in-between stage called prediabetes, where blood sugar is higher than normal but not yet in the diabetic range — an important warning sign and an opportunity to take action before diabetes develops.
Treatment and management
Managing type 2 diabetes focuses on keeping blood sugar within a healthy range to feel well and reduce the risk of complications. For many people, this begins with lifestyle changes: a balanced diet, regular physical activity, losing excess weight, and not smoking. These steps alone can be remarkably effective, and some people are able to bring their blood sugar back to a normal range.
When lifestyle changes are not enough, medication is added. Metformin is usually the first medicine prescribed, and several other classes of medication are available, some of which also protect the heart and kidneys. A smaller number of people may eventually need insulin. Regular monitoring, including periodic HbA1c tests and checks of your eyes, feet and kidneys, is an important part of ongoing care.
Can type 2 diabetes be prevented?
For many people, yes — or at least significantly delayed. Because lifestyle factors play such a large role, the same steps that help manage diabetes also help prevent it. Losing a modest amount of weight if you are overweight, being physically active for at least 150 minutes a week, eating plenty of vegetables, fruit, whole grains and fibre, and limiting sugary drinks and highly processed foods all substantially lower your risk.
If you have prediabetes, these changes are especially powerful and can stop or delay the progression to type 2 diabetes. Knowing your risk — through your weight, waist measurement, family history and, where appropriate, blood tests — lets you act early, when prevention is most achievable.
Complications of type 2 diabetes
When blood sugar stays high over a long period, it can gradually damage blood vessels and nerves throughout the body, which is why managing diabetes well matters so much. The complications of type 2 diabetes develop slowly and are often preventable or delayable with good control, but understanding them helps explain why treatment and monitoring are worthwhile even when you feel completely well.
Long-term high blood sugar can affect several parts of the body. It raises the risk of heart disease and stroke, because diabetes damages blood vessels and often occurs alongside high blood pressure and high cholesterol. It can harm the small blood vessels of the eyes (diabetic retinopathy), a leading cause of vision loss, and the kidneys (diabetic nephropathy), which is why regular eye and kidney checks are part of diabetes care.
Nerve damage, known as diabetic neuropathy, commonly affects the feet, causing numbness or tingling. Combined with reduced blood flow, this makes foot problems and slow-healing wounds more likely, which is why foot care and regular foot checks are emphasised. The encouraging message is that keeping blood sugar, blood pressure and cholesterol within target ranges substantially reduces the risk of all these complications.
Living well with type 2 diabetes
A diagnosis of type 2 diabetes can feel daunting, but it is a condition that responds remarkably well to everyday choices, and most people manage it successfully alongside a full life. The foundation is the same set of habits that benefit everyone, applied a little more consistently: balanced eating, regular activity, maintaining a healthy weight, not smoking, and taking any prescribed medication reliably.
Monitoring is part of living with diabetes. Periodic HbA1c tests show how your average blood sugar is tracking over time, and your healthcare team will also check your blood pressure, cholesterol, kidneys, eyes and feet at regular reviews. Some people also monitor their own blood sugar at home, depending on their treatment. These checks are not about judgement but about catching and addressing issues early.
Emotional wellbeing matters too. It is common to feel overwhelmed at times, and diabetes has been linked with a higher risk of low mood. Support from healthcare professionals, diabetes education programmes, and connecting with others who have the condition can all help. Setting small, realistic goals rather than aiming for perfection tends to be more sustainable and just as effective over the long run.