What is type 2 diabetes?
Type 2 diabetes is sometimes called adult- or maturity-onset diabetes. This is because it usually first appears in middle-aged or older people, although it is becoming more common in children and adolescents with a family history of type 2 diabetes and/or those who come from a high-risk group.
In type 2 diabetes, the body either doesn’t release enough insulin or the body makes insulin in normal amounts, but the body’s cells do not respond to it. This results in higher than normal levels of glucose (a type of sugar) in the blood.
The high blood glucose levels that occur as a result of diabetes can cause a range of different symptoms. If not controlled, over time, these may cause problems and complications, such as vision loss, kidney disease, foot and leg problems, and an increased risk of stroke and heart disease.
In Australia, it's estimated that almost one million people have type 2 diabetes, but almost half of these people may not be aware that they have it.
Apart from type 2 diabetes, there are also two other main types of diabetes:
In type 1 diabetes, the body makes little or no insulin. Gestational diabetes is similar to type 2 diabetes, but only occurs in women during pregnancy. To find out more, read our information on type 1 diabetes and gestational diabetes.
In people with diabetes, the body’s usual ways of controlling blood glucose levels do not work properly, which results in high blood glucose.
When you eat food, it is digested in the stomach, which then transports any sugar (glucose) — and other nutrients that the food contains — into your blood. The glucose is used by your body as energy for a whole range of important processes, including providing your muscles with energy during exercise.
Normally, insulin controls the amount of glucose in the blood and keeps it at a safe and healthy level. Normal glucose levels are between 4.0 and 7.7 millimoles [mmol] per litre [L].
Insulin helps glucose to enter the body’s cells and is also involved in storing excess glucose in the liver, and in the fatty (adipose) tissues of the body. It is produced by the pancreas when blood glucose levels rise — for example after a meal.
In type 2 diabetes, one of two things can happen: either the pancreas doesn’t make enough insulin, or the cells in the body that take up and store glucose (e.g. the liver and fatty tissues) don’t respond properly to the insulin made by the pancreas (this is known as ‘insulin resistance’). In both cases, the end result is higher than normal blood glucose levels (more than 8 mmol of glucose per litre of blood).
If you would like to find out more, read our information about insulin and the pancreas.
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- Type 2 diabetes: priorities and targets. NPS NEWS (www.nps.org.au/health_professionals/publications/nps_news/current/type_2_diabetes_priorities_targets)
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