Hypoglycaemia

Hypoglycaemia

Hypoglycaemia happens when the blood glucose level is less than 4 mmol/l, or where symptoms of hypoglycaemia are experienced at a level close to this.

Key points to remember about diabetes and hypoglycaemia

Your child needs urgent treatment for hypoglycaemia.

  • hypoglycaemia can be mild, moderate or severe
  • the amount of glucose needed to treat hypoglycaemia depends on your child's size, insulin plan, recent insulin dose and recent exercise
  • treatment is urgent

What is hypoglycaemia?

Hypoglycaemia happens when the blood glucose level is less than 4 mmol/l, or where symptoms of hypoglycaemia are experienced at a level close to this. Hypoglycaemia can be mild, moderate or severe.

See a short video about hypoglycaemia at the Starship Children's Health website.

Thumbnail image of a video still showing two women and a boy seated and talking.

What are the main causes of hypoglycaemia?

  • a recent insulin dose that was too large for the body's requirements
  • missed or delayed meals, or eating too little carbohydrate at meals
  • exercise, without decreasing the insulin or without eating additional carbohydrate
  • alcohol intake

What are the symptoms of mild to moderate hypoglycaemia?

Symptoms may include one or more of the following:

  • looking pale
  • feeling shaky
  • headache
  • feeling sweaty
  • feeling hungry
  • feeling dizzy
  • change in behaviour or irritability
  • lack of concentration
  • crying
  • confusion
  • blurred vision

Babies and young children may not say that they are feeling unwell and may show few signs of hypoglycaemia.

What makes hypoglycaemia at night more likely?

Hypoglycaemia at night is more likely to occur after increased levels of activity during the day or if a child/adolescent has eaten less or is unwell.

The risk of night hypoglycaemia can be minimised as follows:

  • target blood glucose level at suppertime/bedtime should be 6 to 10 mmol/l (6 to 12 mmol/l in infants or children under 5 years) - if less than 6 mmol/l, add an additional 5 to 20g of carbohydrate to the supper carbohydrate allowance
  • you should recheck the blood glucose level a few hours later if blood glucose levels at supper have been less than 6mmol/l

What is hypoglycaemia unawareness?

Hypoglycaemia unawareness is where hypoglycaemia is occurring as measured by a blood glucose test or observed by others but the child with diabetes is not aware of it.

Toddlers and young children who are newly diagnosed may not sense hypoglycaemia very effectively and may not be able to verbalise this, so detection of hypoglycaemia in these particular groups relies solely on others. Gradually children should learn how to recognise and express their hypoglycaemia symptoms.

In older children and adolescents, hypoglycaemia unawareness can develop following frequent hypoglycaemia episodes. This is a dangerous condition where hypoglycaemia can develop quickly and increase the risk of severe hypoglycaemia.

What is the treatment for mild-moderate hypoglycaemia in patients with type 1 diabetes?

The amount of glucose needed to treat hypoglycaemia depends on your child’s size, insulin plan, recent insulin dose and recent exercise. Treatment is urgent.

Step 1

10 to 20g of fast acting carbohydrate (amount dependent on age and size of your child).

Examples include:

  • 125 ml juice drink
  • 10 to 20g of glucose tablets - tablets are not suitable for children under 5 years due to the risk of choking

Step 2

Symptoms should resolve within 5 to 10 minutes of step 1 treatment.

Recheck blood glucose level after 10 minutes and if blood glucose level is 4 mmol/L or above give 10 to 20g 'snack' of slow acting carbohydrate or bring next scheduled meal forward in place of snack if due within half an hour. Snack examples include:

  • a slice of bread
  • 200 ml milk
  • 6 small dry crackers or 2 large dry crackers
  • an apple
  • a banana

If blood glucose level remains below 4 mmol/L at 10 minute check, repeat step 1 treatment.

How do I manage severe hypoglycaemia?

The symptoms of severe hypoglycaemia are a blood glucose level less than 4 mmol/l and:

  • extreme drowsiness or disorientation
  • being unconscious, or
  • having a convulsion

In severe hypoglycaemia, you need to make a judgement about whether it is safe to treat with sweet foods or drink. The child needs to be conscious and cooperative enough to be able to swallow. If they are too drowsy or disoriented to understand and follow instructions, don't give them anything by mouth.

  • call for assistance
  • place the child in recovery position and ensure clear airway
  • call for an ambulance (dial 111 within New Zealand; use the appropriate emergency number in other countries) and tell them it is a child with diabetes having a severe hypo

How do I give a glucagon injection with the GlucaGen™ hypokit for severe hypoglycaemia?

The GlucaGen™ hypokit contains a synthetic form of glucagon. Only parents and others who have been appropriately trained can give a glucagon injection. 

You can see a video about giving a glucagon injection for severe hypoglycaemia at the Starship Children's Hospital website.

Thumbnail image of a video still showing a pair of hands giving an injection into skin

What happens during recovery from severe hypoglycaemia following glucagon injection?

  • the child or adolescent should generally wake within 5 to 10 minutes of receiving the glucagon - if they have had a convulsion, it should usually be short and does not cause permanent damage
  • when the child or adolescent is awake, give sips of sweet fluid (such as juice drink, lemonade)
  • severe hypoglycaemia can cause vomiting and/or severe headache - continue to offer sips of sweet fluid until the child can take small amounts of slow acting carbohydrate (crackers)
  • monitor the blood glucose levels every 15 minutes
  • call your diabetes team for advice on insulin doses following the episode
  • your child will need follow up review at diabetes clinic

The Paediatric Society of New Zealand acknowledges the cooperation of the Starship Children's Hospital, Auckland District Health Board.  The content on this page has been produced in collaboration with the National Clinical Network Children and Young People's Diabetes Services. 

This page last reviewed 20 May 2015.
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