Low blood glucose is when blood glucose is less than 4.0

People with diabetes may develop low blood glucose as a result of:²

• too much insulin or other blood glucose lowering medication;
• inadequate or delayed carbohydrate intake after their usual insulin or oral medication dose;
• exercise without adequate carbohydrate intake;
• the setting of other illness; or
• excessive alcohol intake.

Competitors in ultra-marathon endurance events, who do not have diabetes, can also become energy deplete and develop low blood glucose levels requiring first aid management.

Hypoglycaemic events range from those that can be self-managed, to severe episodes, where medical help is needed.

The brain requires a continuous supply of glucose to function normally. When blood glucose levels fall below normal levels symptoms and signs may include:

• anxiety, agitation
• sweating
• pallor (pale skin), especially in young children¹
• a rapid pulse
• shaking, trembling or weakness
• nausea or hunger
• light headedness or dizziness
• headache
• mood or behavioural changes, confusion, difficulty concentrating
• visual disturbance, slurred speech
• difficulty or inability to follow instructions
• drowsiness, unresponsiveness (loss of consciousness) or

If a person with diabetes has a diabetes management plan, then that plan should be followed.  If a person with diabetes reports low blood glucose or exhibits symptoms or signs of hypoglycaemia:

• Stop any exercise, rest and reassure.
• If the person is able to follow simple commands and swallow safely, ANZCOR recommends that first aid providers administer 15 to 20 grams glucose tablets (4 to 5 x 4 gram glucose tablets) for treatment of symptomatic hypoglycaemia [CoSTR 2020, strong recommendation, very low certainty of evidence].^3,,4,,5
• If glucose tablets are not available, we suggest administering confectionary including:
  • Glucose gels (15 g of glucose gel)⁷
  • Honey or sugar (3 teaspoons)
  • Fruit juices (approx. 200 mL)
  • Sugary drinks or sugar-sweetened beverages (approx. 200 mL), but DO NOT administer ‘diet’ or ‘low-cal’ or ‘zero’ or ‘sugar free’ beverages
  • Mentos® (5 to 10 mints) [CoSTR 2015, weak recommendation, very-low-quality evidence]²
  • Skittles® (20 to 25 candies)
  • Jelly beans (5 to 20 beans depending on the brand).
  • Monitor for improvement – resolution of symptoms would be expected within 15 minutes.
  • If symptoms or signs of hypoglycaemia persist after 10 to 15 minutes, and the person is still able to follow simple commands and swallow safely, administer a further 4 x 4g glucose tablets or alternatives as listed above.
  • Once recovered, give a snack with longer acting carbohydrate, for example: 1 slice of bread / sandwich OR 1 glass of milk OR 1 piece of fruit OR 2-3 pieces of dried fruit OR 1 snack size tub of yoghurt (not diet or ‘sugar free’ yogurt). If it is a usual meal time, then eat that meal.
  • If the person deteriorates, does not improve with treatment, has a seizure or is unconscious, call for an ambulance and stay with the person.

• If the person is unresponsive and not breathing normally, commence resuscitation following the Basic Life Support Flowchart [ANZCOR Guideline 8].

If the person is unconscious but breathing, position the person into a lateral, side lying (lateral recumbent) recovery position as opposed to leaving them supine, and ensure the airway is open and clear, and call an ambulance [ANZCOR Guideline 3].

Insulin Pumps

If the person is wearing an insulin pump, then they themselves may ‘suspend’ their own pump if part of a personal diabetes management plan.

First aiders should not touch any insulin pump being worn by the person.  They should manage and provide treatment for hypoglycaemia as listed above.

Family members of, and carers for children and adults with diabetes may be trained in the use of the GlucaGen® HypoKit. This kit contains an injection of glucagon, which works by triggering the liver to release stored glucose, resulting in raised blood glucose levels. The glucagon is administered by injection.

• The usual dose for adults and children who weigh more than 25 kg is 1 mg (1 mL). Use the content of the full syringe (1 mL).
• The usual dose for children who weigh less than 25 kg is 0.5 mg (0.5 mL). Gently push the plunger until it is at the 0.5 mL mark on the syringe to make sure there is 0.5 mL liquid left in the syringe.
• If you do not know how much the child weighs:

• Give a child under 6 years of age 0.5 mg (0.5 mL).
• Give a child 6 years of age and older 1 mg (1 mL).

If trained to do so, give Glucagon in the case of a severe hypoglycaemic event, when the person is unconscious or having a seizure, and/or is unable to swallow safely.⁴

The effectiveness of glucagon is reduced when food has not been eaten for more than 12 hours or in individuals with advanced liver disease.

Hyperglycaemia means having a high blood glucose level. Common causes of hyperglycaemia include inadequate levels of insulin or incorrect doses of diabetes oral medications, illness, infections, excess carbohydrate intake, and stressful situations. Many people do not experience symptoms from hyperglycaemia until their blood glucose levels are extremely high. Hyperglycaemia can also occur at the time of initial diagnosis of diabetes, and may go unrecognised until the person is clearly unwell. If untreated, the person gradually deteriorates, and can go into life threatening conditions such as Diabetic ketoacidosis (DKA), Hyperosmolar hyperglycemic state (HHS) and coma.

When blood glucose levels remain above normal levels symptoms and signs may include:

• excessive thirst
• frequent urination of large volumes
• dry skin and mouth (signs of dehydration)
• recent weight loss
• excessive tiredness
• rapid pulse
• nausea and vomiting
• abdominal pain
• rapid and deep breathing
• fruity sweet smell of acetone on the breath (similar to paint thinner or nail polish remover) and
• confusion, a deteriorating level of consciousness, or unresponsiveness.

If a person with diabetes has a diabetes management plan then that plan should be followed.  If the person has no management plan and has symptoms or signs of hyperglycaemia they should be assessed by a health care professional.

• If the person is unresponsive and not breathing normally, commence resuscitation following the Basic Life Support Flowchart [Refer to ANZCOR Guideline 8]
• If the person is unconscious but breathing, position the person into a lateral, side lying (lateral recumbent) recovery position as opposed to leaving them supine, and ensure the airway is open and clear, and call an ambulance. [Refer to ANZCOR Guideline 3].

If trained to do so and a glucometer is available, checking the person’s blood glucose level will guide management, and can confirm hypoglycaemia or hyperglycaemia. Normal blood glucose concentrations are between 4.0 and 7.0 mmol/L. 

A blood glucose level between 3.0 mmol/L and 4.0 mmol/L is an “alert value”, meaning that to prevent progression to a more serious, clinically important hypoglycaemia, it is time for a normal food intake, either a snack or meal, depending on the time of day and usual food intake habits.⁶

Clinically important hypoglycaemia is defined as a blood glucose level less than 3.0 mmol/L, where there is decreased neuro-cognitive function (reasoning ability or orientation) and increased morbidity (illness) and mortality.⁶

Symptoms of hypoglycaemia may be the same as other conditions such as stroke, epilepsy, or migraine. 

If trained, checking a blood glucose will improve the accuracy of diagnosing hypoglycaemia. ANZCOR suggest if blood glucose concentration is normal, and symptoms and signs of hypoglycaemia persist, consider other diagnoses [CoSTR 2015: weak recommendation/low quality evidence].²

Hyperglycaemia is defined as a blood glucose level above the normal reference range.