Type 1 diabetes is caused by a combination of genetic (inherited from your family) and environmental factors. If a person who has a genetic tendency to develop diabetes comes in to contact with a trigger in the environment, then diabetes may develop. This can happen at any age.
Many people who have a genetic tendency to develop diabetes do not get diabetes, so researchers are trying to find out more about what the environmental triggers are. These triggers are poorly understood but may be common things in our environment such as viruses or stress. The trigger may be different for different people.
If diabetes is triggered, your body's immune system, which normally protects you from infection, begins to attack the insulin-making cells, which are called beta cells, in your pancreas. Your immune system starts to destroy the beta cells, causing a decrease in insulin production. It can take from a few weeks to a few years for all the beta cells to be destroyed.
Symptoms of diabetes do not occur until more than 90% of the beta cells have been destroyed. This means that it is difficult to tell that you are developing diabetes until the symptoms of diabetes occur.
Insulin deficiency and type 1 diabetes
Insulin is a hormone that acts as a 'key' to move glucose from your blood into your body’s cells where it is used for energy. After you eat, glucose from your food is absorbed through the lining of your stomach into your blood, which increases the glucose levels in your blood.
In someone who doesn’t have diabetes, your body responds to this increase in glucose by releasing insulin from your pancreas. The insulin helps move the extra glucose from your blood into your cells. Blood-glucose levels return to normal.
In type 1 diabetes, your pancreas makes little or no insulin, so glucose stays in your blood. This means your blood-glucose levels stay high – known as hyperglycaemia. Also, your cells do not get the glucose they need for energy, so they use fats to provide energy instead. If your body uses fat for energy too often, it can lead to a dangerous build-up of waste products called ketones.
Some parts of your body, in particular your brain and red blood cells, need some glucose to function properly.
What are ketones and why are they a problem?
Ketones are a type of acid that is produced when your body burns fat for energy instead of glucose. Using fat for energy some of the time is normal. However, if it goes on for too long it can produce high levels of ketones in your blood. This can be dangerous as it can lead to coma or even death.
Treating type 1 diabetes means replacing insulin to 'unlock' your cells, letting glucose in and keeping your blood glucose level stable. Successful management of type 1 diabetes involves having insulin injections and balancing what you eat with how active you are each day.
Read more about insulin.
Did you know?
- Diabetes cannot be caught from another person – it is not contagious.
- Type 1 diabetes is not caused by eating too much sugar or any other foods.
- There is nothing you could have done differently to prevent you or your child from getting type 1 diabetes.
- You cannot grow out of type 1 diabetes and it does not change into type 2 diabetes as you get older.