Type 1 diabetes results from a problem with the immune system that destroys the cells of the pancreas which produce insulin.
To compensate for the loss of these cells, people with Type 1 diabetes have to inject replacement insulin every day. Unlike Type 2 diabetes, Type 1 is not linked to lifestyle factors such as diet, exercise and weight. Between 10-15% of all people with diabetes have Type 1.
Insulin allows cells to generate energy from the food that we eat. Specifically, insulin enables cells to use glucose as a source of fuel.
In Type 1 diabetes, glucose from food remains unused by the cells and builds up in the bloodstream. High levels of glucose in the blood are toxic, damaging blood vessels, nerve fibres and the kidneys. Consequently, the body resorts to clearing glucose from the blood via urine. This leads to increased visits to the toilet, which leads to increased thirst, both of which are common symptoms of untreated diabetes. With all diabetes, the toxic effects of glucose develop over time. Damaging effects are often first noticed in the eyes, the kidneys and the nerves, leading to blindness and amputations. The raised blood glucose of diabetes also results in cardiovascular disease, the most deadly disease in the developed world.