Dr Rebecca Lawson
Why type 2 diabetes can creep up quietly
Type 2 diabetes is common in the UK, and it often develops slowly. The body becomes less responsive to insulin, the hormone that moves glucose from the blood into cells for energy. Over time, blood glucose levels can rise. Because this happens gradually, many people put early symptoms down to getting older, a busy week, or simply feeling run down. That is understandable, but it is why the condition can go unnoticed.
The good news is that type 2 diabetes is not a sudden event. There is usually a long run-up, sometimes called prediabetes or non-diabetic hyperglycaemia. During this stage, a blood test can show that glucose levels are higher than normal but not yet in the diabetes range. Spotting that window matters. It is a chance to make changes, and for some people, to prevent or delay type 2 diabetes altogether.
The signs that deserve a second look
Some symptoms are classic, and they are worth taking seriously if they appear together or persist. They include:
- Increased thirst. You may feel unusually thirsty, even when you have not been active or eaten salty food. It is a persistent need for more fluid.
- Passing urine more often. This can include waking up several times at night to go to the toilet. You may notice a cycle of drinking and urinating more.
- Persistent tiredness. Not the usual end-of-week tiredness, but a heavy, flat fatigue that does not improve much after rest. Glucose is not reaching your cells efficiently, so your body is running on the wrong fuel.
- Slow healing cuts and sores. A small cut, blister, or insect bite that takes weeks to heal, or keeps coming back, is a reason to get checked.
- Unexplained weight loss. Losing weight without trying can happen when the body starts breaking down fat and muscle for energy because it cannot use glucose properly.
- Blurred vision. High glucose levels can change the shape of the lens in your eye, making your sight blurry. This can come and go.
These symptoms do not automatically mean diabetes. They can have other causes. But if they are new, persistent, or happening together, they are a signal to speak to a clinician rather than wait.
Less obvious clues and higher-risk groups
Not everyone gets the textbook signs. Some people notice:
- Recurrent infections. Thrush, urinary tract infections, or skin infections that keep returning. High glucose can make it easier for infections to take hold.
- Tingling or numbness. Pins and needles, burning, or reduced feeling in the hands or feet.
- Itchy skin or dark velvety patches. These may appear in skin folds such as the neck, armpits, or groin.
- Irritability or difficulty concentrating. Changes in glucose can affect mood and focus.
Some people have a higher risk of type 2 diabetes, including those who are over 40 (or over 25 for people of South Asian, Black African, or Caribbean heritage), have a parent or sibling with diabetes, have had gestational diabetes or polycystic ovary syndrome, or carry extra weight around the middle. Risk also rises with age, smoking, high blood pressure, and some medications. If any of these apply to you, a routine check can be especially valuable — even if you feel fine.
What to do if you notice these signs
Book an appointment with your GP or speak to a pharmacist. Be specific about what you have noticed and for how long. For example: "I have been waking twice a night to urinate for the past month, and I am constantly thirsty." A simple blood test can measure your HbA1c, which shows average glucose levels over the previous two to three months. In the UK, an HbA1c of 48 mmol/mol or above is usually diagnostic of diabetes; 42 to 47 mmol/mol suggests prediabetes. A random blood glucose test may also be used if symptoms are clear.
Do not rely on a home finger-prick test unless a clinician advises it. If you are in England and aged 40 to 74, you may be eligible for a free NHS Health Check, which includes a diabetes risk assessment. In other parts of the UK, your GP surgery can advise on local checks. If you have symptoms that are severe — such as vomiting, deep rapid breathing, confusion, or a fruity smell on your breath — seek urgent medical help.
How early action changes the long term
Getting diagnosed early is not about labelling yourself. It is about protecting your future. Type 2 diabetes that is left untreated can damage blood vessels and nerves over time, raising the risk of heart attack, stroke, kidney disease, sight loss, and foot problems. Early treatment — whether that is lifestyle support, medication, or both — can reduce those risks substantially. Some people who make significant changes soon after diagnosis go into remission, meaning their blood glucose returns to the normal range without medication. Remission is not possible for everyone, but it is a realistic goal for some.
Small, steady changes matter: regular movement, more fibre, fewer sugary drinks, better sleep, and weight loss if needed can improve insulin sensitivity. Ask your GP about local prevention programmes and structured education. You do not have to overhaul everything at once. Start with one change you can keep. The earlier you act, the more options you have — and the more you can protect the life you want to live.
