Silent Assassin: what you need to know about diabetes and how to calculate your risk of developing it

Diabetes is a chronic condition that affects the way the body processes blood sugar, known as glucose. For our bodies to work properly, we need to maintain a healthy level of glucose in our blood, as it is the body's main source of energy.

This comes from the carbohydrate foods such as bread, pasta, rice, cereals, fruits, starchy vegetables, milk and yoghurt. When we eat these foods, our blood stream carries the glucose around our bodies, where our cells convert it into energy.

Insulin, a hormone produced in the pancreas, breaks down the glucose so it can enter the cells. But if you have diabetes, it means your pancreas makes too little insulin, or none at all. As a result, the glucose you eat will stay in your blood instead of being turned into energy, and high levels of glucose in your blood can cause damage to your heart, brain, kidneys, eyes and feet.

There are three main types of diabetes, plus a condition known as "pre-diabetes".

Type 1 diabetes is an autoimmune condition in which the immune system activates and destroys the cells in the pancreas that produce insulin. While it is not known what causes this reaction, it is not linked to modifiable lifestyle factors, there is no cure, and it cannot be prevented. It represents about 10-to-15 per cent of all cases of diabetes, and is managed with insulin injections several times a day or with the use of an insulin pump. Onset is usually abrupt and the symptoms obvious. These include excessive thirst and urination, unexplained weight loss, weakness, fatigue and blurred vision.

In type 1 diabetes, the pancreas - a large gland behind the stomach - stops making insulin because the cells that make the insulin have been destroyed by the body's immune system. Without insulin, the body's cells cannot turn glucose - sugar - into energy.

In type 2 diabetes, the body becomes resistant to the normal effects of insulin or gradually loses the capacity to produce enough insulin in the pancreas. It tends to run in the family, and has been associated with modifiable lifestyle risk factors.

Some people may be able to slow the progression of the condition through changes to diet and increasing physical activity. While type 2 diabetes usually develops in adults over the age of 45, it is increasingly occurring in younger age groups, including children.

It is managed with a combination of regular physical activity, healthy eating, and weight reduction, but - as it is often progressive - many people will eventually need oral medications or insulin injections over time. Aboriginal or Torres Strait Islanders, people from the Pacific islands or with Indian or Chinese backgrounds are at greater risk of developing the disease.

There is currently no cure, but effectively managing it with lifestyle modifications and medication is the best way to prevent diabetes-related complications.

Symptoms can include:

Note: Diabetes Australia points about that this information is of a general nature only and should not be substituted for medical advice or used to alter medical therapy. It does not replace consultations with qualified healthcare professionals to meet your individual medical needs.

Gestational diabetes mellitus occurs during pregnancy, and while most women will no longer have diabetes after the baby is born, some will continue to have high blood glucose levels after delivery.

It is the fastest growing type of diabetes in Australia, affecting thousands of pregnant women who have an increased risk of developing type 2 diabetes in the future. The baby may also be at risk of developing type 2 diabetes later in life. Gestational diabetes can often be managed with healthy eating and regular physical activity. However, but some women may need medication (metformin) and/or insulin injections.

Pre-diabetes is a condition in which blood glucose levels are higher than normal, but not high enough to be diagnosed as type 2 diabetes. It has no signs or symptoms, and people with pre-diabetes have a higher risk of developing type 2 diabetes and cardiovascular disease.

Two million Australians have pre-diabetes, and without sustained lifestyle changes - including healthy eating, increased activity and losing weight - about one in three will go on to develop type 2 diabetes.

Calculate your risk of developing diabetes at diabetesaustralia.com.au/risk-calculator