This page is adapted and borrowed with gratitude from a parent’s circular on, and is an introduction to understanding the mechanics and treatments of type 1 diabetes, particularly in children.

What is Type 1 Diabetes?

Type 1 diabetes is an autoimmune disease in which the insulin-producing cells in the pancreas have been destroyed and can no longer make the hormone insulin.  It is also known as “insulin dependent diabetes”.

What is insulin and what happens when you don’t have any?

All the body’s cells require glucose for energy, and insulin is the catalyst that transfers glucose from the bloodstream into individual cells.  In the absence of insulin, this transfer cannot take place.  The cells are starved of energy and the glucose remains in the bloodstream.  The body responds to the cells’ continuing need for energy by releasing stored glucose from the liver and muscles (starvation response), but this in turn cannot be accessed by the cells without insulin, so the blood glucose level rises further.   The body attempts to reduce the blood glucose level by expelling glucose via the urine, leading to the person becoming rapidly dehydrated.   Meanwhile, the body begins to break down fat reserves to produce glucose, a process which also produces an acidic toxic by-product called ketones.  Again, neither the glucose nor the ketones can be metabolised without insulin, and the body attempts to rid itself of the ketones via the lungs and by vomiting .  The person rapidly loses weight, becomes severely dehydrated and exhausted.  Unless insulin is given, they will inevitably die of Diabetic Ketoacidosis (DKA).

Is there a cure?

Not yet.  Type 1 diabetes is a life-long chronic illness which requires treatment with insulin by injection and/or pump infusion.

What are the aims of the treatment?

To achieve normal blood glucose (BG) levels (4-7 mmol/l).

Does it matter if BG levels fluctuate?


If the BG is too low (<4.0mmol/l – “hypoglycaemia”), there is insufficient glucose in the blood for the brain to function properly.  If glucose is not eaten quickly, the person will lose consciousness, may have seizures, and may suffer brain damage or death.

If the BG is too high (>7.0mmol/l), there are unlikely to be any immediate symptoms, but the cumulative effect of repeatedly raised BG levels over time leads to diabetic complications (blindness, kidney failure, amputations, cardiovascular disease, etc.).

If the BG is very high (>14.0mmol/l – “hyperglycaemia”), this indicates a lack of insulin, which must be investigated.  If no action is taken, there is a risk of DKA developing, which is a life-threatening condition requiring immediate hospital treatment.

What factors affect blood glucose levels?

  • Insulin – lowers BG
  • Carbohydrate-containing foods (raise BG)
  • Exercise (lowers BG in the presence of insulin, but raises BG if there is insufficient insulin available)
  • Illness (usually raises BG, but vomiting bugs can lead to hypos)
  • Stress and excitement (can raise or lower BG due to the action of adrenaline and other hormones)
  • Growth hormones (usually raise BG)
  • Pattern of BGs in the previous 24-48 hours

Do you have to watch what you eat?

Yes and no!  Type 1 people can eat the same healthy diet that is recommended for everyone, including sweet treats in moderation.  Insulin doses are matched to the carbohydrate content of the food, so this must be counted as accurately as possible.  Other factors to consider are the GI of the carbs, and the fat content of the meal, as these affect the speed of digestion and the timing of glucose appearing in the bloodstream.  We want to match the insulin delivery to this.

Is there any activity you can’t take part in because of type 1 diabetes?

Absolutely not!  Everything is possible with a little planning and forethought.  BG testing, appropriate snacks, maybe a little top up of insulin………

Can diabetes affect cognitive ability and academic performance?

Fluctuating blood glucose levels can have a significant impact.  High BGs lead to tiredness and poor concentration.  Hypos directly affect the brain’s capacity for higher reasoning (the inability to communicate clearly being one of the signs of a hypo), and a child will be unable to think and concentrate both during the hypo and for some time afterwards.

What is an insulin pump?

This is a sophisticated device for administering insulin as an alternative to injections.  It is about the size of a pager, and contains a cartridge of insulin linked by a thin flexible tube to a teflon cannula that sits under the skin.  The cannula and infusion set must be replaced in a new site at least every 3 days.  The pump can be programmed to deliver insulin in small increments throughout the day (mimicking a normal pancreas), and the user can give additional amounts of insulin to cover meals and snacks.  If BG levels are outside the normal range, the user can temporarily alter the rate of insulin delivery to try and remedy this.

Most pumps are not waterproof and must not be immersed.  It is also recommended that they are disconnected for contact sports, to prevent injury to the wearer.  As a valuable article, it will need to be kept safe when not attached.  The pump must also be kept away from powerful magnets such as MRI machines.

The main risk associated with pump usage is that, unlike people using an injection regime, insulin pump users have no long-acting insulin, so that in the event of a problem with the pump or the cannula which prevents insulin delivery, they have no depot of insulin in their body.  BG levels and ketones will rise rapidly and within a matter of hours the person could be at risk of developing DKA.  This can be prevented by regular BG testing.  If high levels persist despite giving more insulin via the pump, the person should take insulin by injection, and the entire infusion set must be replaced.