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Causes of type 1 diabetes

If you have just been diagnosed with type 1 diabetes, you are probably wondering, ‘Why me?’ It is important to know it is not your fault. Type 1 diabetes is not caused by any type of diet or lifestyle. It isn’t caused by anything that you did or didn’t do, and there was nothing you could have done to prevent it.
Content last reviewed and updated: 13.03.2024

A woman doing a finger prick test to check blood glucose levels

What causes type 1 diabetes?

More than 50 genes have been identified that can influence a person’s risk of developing type 1 diabetes, but genes are only part of the cause. Scientists are also investigating the environmental factors that may play a role.

What is known is that:

  • Destruction of insulin-producing beta cells is due to damage inflicted by your immune system
  • Something triggered your immune system to attack your beta cells
  • Certain genes put people at a greater risk of developing type 1 diabetes, but are not the only factors involved
  • While there are no proven environmental triggers, researchers are looking for possible culprits, such as viral infections and the microbes that live in our guts

Is type 1 diabetes genetic?

While 90 per cent of people who develop type 1 diabetes have no family connection with the condition, genetic factors can pre-dispose people to developing type 1 diabetes.

Certain genes are associated with type 1 diabetes risk. However, having these genes alone is not enough to cause someone to develop type 1 diabetes. It is thought that an additional environmental trigger causes type 1 diabetes to develop.

Can you be born with type 1 diabetes?

Type 1 develops when your immune system attacks the insulin-producing beta cells in your pancreas and this doesn’t happen overnight. It’s very rare for anyone under six-months-old to be diagnosed with type 1 diabetes.

Can type 1 diabetes develop because of your lifestyle?

Type 1 diabetes does not develop because of your lifestyle. Type 1 diabetes is an autoimmune condition. Diet and activity levels have nothing to do with whether you develop type 1 diabetes or not.

More about type 1 diabetes

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A man drinking a glass of water. One of the signs of type 1 diabetes is to be thirsty a lot.

What are the signs and symptoms of type 1 diabetes?

Find out more about the main signs and symptoms of type 1 diabetes, which include tiredness, thirst, going to the toilet more frequently and weight loss.

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A patient with type 1 diabetes talking to a diabetes nurse

What is the difference between type 1 and type two diabetes?

All types of diabetes cause blood glucose levels to be higher than normal. Find out about the key differences between the major types.

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A microscopic image of immune cells in the spleen. Immune therapies are being researched as part of trying to find a cure for type 1 diabetes.

Type 1 diabetes and other autoimmune conditions

Find out why people who have one autoimmune condition are at greater risk of developing other types of autoimmune disease.