What is diabetes?
Diabetes is a condition where the level of sugar in the blood becomes too high. The pancreas makes insulin, a hormone that helps move glucose out of the blood and into your cells to be used for energy. In diabetes, the body either does not make insulin or cannot use it properly, so glucose builds up in the blood. Over time, diabetes that is not well controlled can damage organs such as the heart, kidneys and eyes.
What causes diabetes?
There is no single cause of diabetes, and the reasons differ between the types. Type 1 diabetes is not caused by lifestyle. It is an autoimmune condition, where the immune system attacks the cells that make insulin. Type 2 diabetes develops from a mix of things, including genetics, excess weight, inactivity and age, so diet is one factor among several rather than the whole story. A sedentary lifestyle, ongoing stress and eating patterns can all add to the risk of type 2 diabetes.
Common symptoms of diabetes
Diabetes can show up in several ways, including needing to pass urine often, feeling very thirsty and feeling hungrier than usual. Some people notice numbness or a burning feeling in the feet, wounds that are slow to heal, dry or itchy skin, and lasting tiredness. Changes to your vision and unexplained weight changes can also happen. If you notice any of these, see your GP, who can arrange tests.
Types of diabetes
The main types are:
- Type 1 diabetes usually begins in childhood or the teenage years. The immune system destroys the insulin-making cells, so the body can no longer produce insulin.
- Type 2 diabetes is the most common type and usually appears in adults. The body either makes too little insulin or cannot use it well.
- Gestational diabetes develops during pregnancy, when hormonal changes make the body more resistant to insulin.
How is diabetes diagnosed?
Diabetes is diagnosed by measuring the sugar in your blood, usually more than once and at different times. A high reading raises the possibility of diabetes, but a single reading is not enough to diagnose it in someone without symptoms. In the UK, the main test is HbA1c, which shows your average blood sugar over the past two to three months and does not need fasting; a result of 48 mmol/mol (6.5%) or above points to diabetes. A fasting blood glucose test, taken after about 8 hours without food, is another option, with 7.0 mmol/L or above suggesting diabetes. An oral glucose tolerance test (OGTT) may also be used, where a reading of 11.1 mmol/L or above two hours after a sugary drink confirms it.
How is diabetes treated?
Treatment centres on a healthy lifestyle, including a balanced diet, regular activity, weight management and managing stress.
- Type 1 diabetes needs lifelong insulin treatment.
- Type 2 diabetes is often managed with lifestyle changes, though some people also need tablets or insulin. For some people with obesity who do not respond to other treatments, weight loss (metabolic) surgery such as a gastric bypass can greatly improve blood sugar control, and can sometimes put type 2 diabetes into remission.
- Gestational diabetes is usually managed with diet and activity, though insulin is sometimes needed.
