In type 1 diabetes, the insulin-producing cells in the pancreas are destroyed by the immune system and therefore cannot produce insulin.
The exact cause of the immune system attacking these cells is not clearly understood.
Unlike type 2 diabetes which is usually slow to develop, type 1 comes on very quickly, often within days or weeks.
Typical symptoms may include:
- Increased and constant thirst – termed polydipsia
- Producing excess urine which causes someone to pass urine more frequently – termed polyuria
- Extreme fatigue
- Blurred vision
- Unexplained weight loss
These symptoms are due to too much glucose being in the blood.
This form of diabetes typically occurs in people before the age of 40, and is most commonly diagnosed in childhood or adolescence. There is nothing that can be done to prevent type 1 diabetes which tends to run in families. Those with a close relative with type 1 diabetes have a 6%* chance of developing the same condition.
Currently there is no cure for type 1 diabetes, but it can be managed well with careful control of blood glucose levels, diet and lifestyle, in addition to taking insulin for life.
* NHS Choices