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Information about Diabetes, Type 1

What is it?

This is a summary of information about this condition. For more detailed information we recommend using the NHS Choices website, A link to this can be found in the External Resources tab above.

Diabetes is a lifelong condition that causes a person's blood sugar (glucose) level to become too high.

The hormone insulin, produced by the pancreas, is responsible for controlling the amount of glucose in the blood.

There are two main types of diabetes:
  • type 1 – where the pancreas doesn't produce any insulin
  • type 2 – where the pancreas doesn't produce enough insulin or the body's cells don't react to insulin

What causes it?

Type 1 diabetes is an autoimmune condition, which means the immune system attacks healthy body tissue by mistake. In this case, it attacks the cells in the pancreas.

The damaged pancreas is then unable to produce insulin. So, glucose cannot be moved out of the bloodstream and into cells.

Type 1 diabetes is often inherited (runs in families), so the autoimmune reaction may be genetic.

It's not known exactly what triggers the immune system to attack the pancreas, but some researchers have suggested it may be a viral infection.

A close relative – such as a parent, brother or sister – increases the likelihood of developing type 1 diabetes, there is about a 6% chance of also developing the condition. The risk for people who don't have a close relative with type 1 diabetes is just under 0.5%.

What are the symptoms and signs?

Typical symptoms of type 1 diabetes are:
  • feeling very thirsty
  • passing urine more often than usual, particularly at night
  • feeling very tired
  • weight loss and loss of muscle bulk
The symptoms of type 1 diabetes usually develop very quickly in young people (over a few days or weeks). In adults, the symptoms often take longer to develop (a few months).

These symptoms occur because the lack of insulin means that glucose stays in the blood and isn’t used as fuel for energy. The body tries to reduce blood glucose levels by getting rid of the excess glucose in the urine.

It's very important for diabetes to be diagnosed as soon as possible, because it will get progressively worse if left untreated.

What treatments are available?

Type 1 diabetes can't be cured. Treatment aims to keep blood glucose levels as normal as possible and control of symptoms, to prevent health problems developing later in life.

As the body can't produce insulin, regular insulin injections will be needed to keep the blood glucose levels normal. There are alternatives to insulin injections, but they're only suitable for a small number of patients.

More information

Complications of type 1 diabetes
Diabetes can cause serious long-term health problems. It's the most common cause of vision loss and blindness in people of working age. 

Everyone with diabetes aged 12 or over should be invited to have their eyes screened once a year for diabetic retinopathy.

Diabetes is the reason for many cases of kidney failure and lower limb amputation.

People with diabetes are up to five times more likely to have cardiovascular disease, such as a stroke, than those without diabetes.


NHS Choices website accessed on 09/10/17
Link to the NHS Choices website available in External Resources
Contains public sector information licensed under the Open Government Licence v3.0.

The medicines listed below have been approved for use in the UK. Medicines are listed by brand name and the active ingredient shown in brackets. An inverted black triangle (▼) against the name denotes that the medicine is being tracked for adverse events.

If the medicine you are interested in is not shown you can request it to be included by emailing the name of the medicine to

Medicines for this condition

Forxiga (dapagliflozin)

Zynquista ▼ (sotagliflozin)

Baqsimi (glucagon)

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. We cannot provide individual medical advice. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.