The three major types of diabetes are:
Type 1 diabetes (previously known as insulin-dependent diabetes)
Type 1 diabetes is an auto-immune disease where the body's immune system destroys the insulin-producing beta cells in the pancreas. This type of diabetes, also known as juvenile-onset diabetes, accounts for 10-15% of all people with the disease. It can appear at any age, although commonly under 40, and is triggered by environmental factors such as viruses, diet or chemicals in people genetically predisposed. People with type 1 diabetes must inject themselves with insulin several times a day and follow a careful diet and exercise plan.
Type 2 diabetes (previously known as non-insulin dependent diabetes)
Type 2 diabetes is the most common form of diabetes, affecting 85-90% of all people with the disease. This type of diabetes, also known as late-onset diabetes, is characterised by insulin resistance and relative insulin deficiency. The disease is strongly genetic in origin but lifestyle factors such as excess weight, inactivity, high blood pressure and poor diet are major risk factors for its development. Symptoms may not show for many years and, by the time they appear, significant problems may have developed. People with type 2 diabetes are twice as likely to suffer cardiovascular disease. Type 2 diabetes may be treated by dietary changes, exercise and/or tablets. Insulin injections may later be required.
Gestational diabetes mellitus (GDM)
GDM, or carbohydrate intolerance, is first diagnosed during pregnancy through an oral glucose tolerance test. Between 5.5 and 8.8% of pregnant women develop GDM in Australia. Risk factors for GDM include a family history of diabetes, increasing maternal age, obesity and being a member of a community or ethnic group with a high risk of developing type 2 diabetes. While the carbohydrate intolerance usually returns to normal after the birth, the mother has a significant risk of developing permanent diabetes while the baby is more likely to develop obesity and impaired glucose tolerance and/or diabetes later in life. Self-care and dietary changes are essential in treatment.
What is type 1 diabetes?
Type 1 diabetes (formerly known as Insulin Dependant Diabetes or Juvenile Diabetes) occurs when the pancreas is unable to make enough insulin. Insulin is a hormone that acts as a key to let glucose from the food we eat pass from the blood stream into the cells to provide energy.
While type 1 diabetes affects people of any age, it usually occurs in children and young adults. Type 1 diabetes is the less common form of diabetes, with just 10 to 15 per cent of all people with diabetes having this type.
Type 1 diabetes is an autoimmune disease. The pancreas cannot produce enough insulin because the cells that make insulin have been destroyed by the body’s own immune system.
What is the cause of Type 1 diabetes?
We don’t yet know the exact cause of type 1 diabetes, but we do know that some people carry genes which might make them more likely to get type 1 diabetes. However it can only occur when something such as a viral infection triggers the immune system to destroy the insulin-making cells in the pancreas. This is called an autoimmune reaction.
How is type 1 diabetes treated?Insulin must be replaced so insulin injections are needed to control blood glucose levels. Therefore, people with type 1 diabetes must have insulin every day to live.
The goal of diabetes management is to keep blood glucose levels as close to the normal range as possible as this reduces the risk of developing long term complications. This can be achieved by insulin injections, blood glucose monitoring as well as balancing food intake and physical activity.
At this stage type 1 diabetes can’t be prevented or cured, although there is a great deal of research being done. For example, the INIT II trial.
What are the symptoms?
In diabetes, glucose stays in the blood, causing the blood glucose level to become abnormally high. Symptoms may include:
Signs of DKA
Find out about DKA and managing type 1 diabetes during illness
Type 1 diabetes statistics
What is type 2 diabetes?
Type 2 diabetes is the most common form of diabetes, affecting 85 to 90 per cent of all people with diabetes. It usually develops in adults over the age of 45, but it is increasingly developing at a younger age.
Type 2 diabetes is known as a ‘lifestyle disease’ as it is often triggered by being inactive or carrying excess weight around the abdomen. It tends to run in families and it is not uncommon to have high cholesterol and high blood pressure as well.
Unlike type 1 diabetes where the body produces no insulin, people with type 2 diabetes are still able to produce their own insulin. There may not be enough insulin for the body’s needs and/or the cells in the body are resistant to the action of insulin (insulin resistance).
Type 2 diabetes is a progressive condition and treatment usually needs to change over time so that blood glucose levels can be kept within the target range. In the early stages the body may be producing more insulin than normal, but after having type 2 diabetes for a number of years, the pancreas becomes exhausted and makes less insulin.
The management of type 2 diabetes initially involves regular physical activity, healthy eating and losing excess weight,. This will help the insulin to work more effectively. With time, tablets may be needed and eventually also insulin injections so that blood glucose levels can be kept within the target range.
Losing weight and being physically active can delay the need for tablets or insulin.
Even when medications or insulin are commenced, regular physical activity and healthy eating remain the cornerstone of diabetes management.
People with type 2 diabetes often have no symptoms, so they may have diabetes for a number of years without knowing it. Sometimes the first sign that something is wrong is when they develop a complication of diabetes such as a heart attack, vision problems or a stroke.
Typical symptoms of type 2 diabetes