Hypoglycaemia: A Diabetes Emergency

In Australia, over 1.3 million people are admitted into hospital with diabetes-related complications (AIHW 2026). One of these complications is hypoglycaemia, in which a person's blood glucose level (BGL) drops below 4 mmol/L (Diabetes Australia 2026), also known as a 'hypo'. As a healthcare professional, knowing how to recognise and respond to these episodes quickly can make a real difference to patient outcomes.

How Does the Body Respond to Hypoglycaemia?

The body's most important glucose sensors are located in the brain (the brainstem and hypothalamus), with 30% of blood glucose being used to sustain normal brain activity (Amiel 2021).

When the brain is starved of energy, it will start to shut down certain areas that control memory, balance and stimulate hunger. The brain will also release stress hormones. Following treatment of a hypoglycaemic episode, it can take 40 minutes to re-establish full brain function.

It's crucial to treat hypoglycaemia quickly in order to prevent the person's BGL from continuing to decrease, which can cause drowsiness, seizures and unconsciousness (Diabetes Australia 2026).

It's also important to be aware that not all people with diabetes experience hypoglycaemia. Those treated with either insulin or sulfonylurea tablets (such as gliclazide, glimepiride, glipizide, glibenclamide) are at risk of hypoglycaemia. The remaining glucose-lowering medicines do not cause hypoglycaemia.

Signs and Symptoms of Hypoglycaemia

(Tauchmann 2024)

Hypoglycaemia can be classified into 3 levels:

(ADA 2021)

What Causes Hypoglycaemia?

Hypoglycaemia risk can be divided into key areas for people with diabetes who are prescribed either insulin or a sulfonylurea agent:

Medical issues:

• Strict glycaemic control
• Previous history of severe hypoglycaemia
• Long duration of type 1 diabetes
• Lipohypertrophy at injection sites
• Impaired hypoglycaemia awareness
• Severe hepatic dysfunction
• Heart failure
• Adrenal insufficiency
• Impaired renal function and dialysis
• Terminal illness
• Cognitive dysfunction and dementia.

Lifestyle issues:

• Increased exercise (relative to usual)
• Rehabilitation programs
• Alcohol
• Increasing age
• Early pregnancy
• Breastfeeding
• Lack of or inadequate blood glucose monitoring
• Religious fasting
• Weight loss.

Note: Hypoglycaemia can be delayed for up to 12 hours following exercise (Diabetes Australia 2026).

Carbohydrate intake issues:

• Reduced carbohydrate intake and absorption
• Food malabsorption, i.e. gastroenteritis
• Coeliac disease
• Bariatric surgery.

(JBDS-IP 2023)

For people admitted into hospital with diabetes, hypoglycaemia risks may also include:

Insulin prescribing errors:

• Inappropriate use of 'stat' or PRN rapid/short-acting insulin
• Confusion about insulin name, dose, and concentration
• Misinterpreting unclear orders on medication charts
• Inaccurate medication history and failure to perform medication reconciliation upon admission.

Medical issues:

• Incorrect type of insulin or glucose-lowering medication prescribed and administered
• Change of insulin administration site
• Intravenous insulin with or without glucose infusion
• Failure to monitor BGLs adequately whilst intravenous insulin infusion is in place
• Inadequate mixing of intermediate or pre-mixed insulins
• Sudden discontinuation of long-term corticosteroids
• Recovery from acute illness or stress
• Mobilisation after illness.

Carbohydrate intake issues:

• Missed or delayed meals
• Less carbohydrate than normal
• Change in the timing of the biggest meal of the day
• Lack of access to usual between-meal or bedtime snacks
• Prolonged starvation or fasting time
• Vomiting
• Reduced appetite.

Enteral/parenteral feeding issues:

• Blocked/displaced tube
• Change in feed regimen
• Discontinuation of enteral feed
• Discontinuation of TPN or IV glucose
• Insulin or sulfonylurea medicines administered at an inappropriate time to feed regimen
• Feed intolerance.

(JBDS-IP 2023)

When people who have diabetes use the same site to inject insulin, they can develop fatty, fibrous and hardened areas, called lipohypertrophy. This can lead to erratic, delayed, or incomplete subcutaneous insulin absorption, potentially prompting the person to increase their dose on their own.

If the person then administers that higher dose of insulin in a non-affected area, they are at risk of a severe hypoglycaemic episode, because they are absorbing 100% of that insulin, as opposed to injecting it into the affected areas of lipohypertrophy.

Those with impaired renal function, including patients on haemodialysis, will have an increased risk of hypoglycaemic episodes. This is because people need less insulin once they're on dialysis, as their kidneys clear insulin more slowly. Furthermore, as the kidneys (or renal function) deteriorate, they are unable to remove the byproducts of these medicines.

Individuals with chronic kidney disease, heart failure and/or cardiovascular disease also have a higher rate of severe hypoglycaemic episodes than those without comorbidity. Chronic kidney disease (CKD), heart failure (HF), and cardiovascular disease (CVD) are deeply connected in a two-way, destructive feedback loop called cardiorenal syndrome. Damage to the heart harms the kidneys, and failing kidneys force the heart to work harder, accelerating disease progression, hospitalisations, and mortality risk (Kalra 2026).

Management of Hypoglycaemia

The management of hypoglycaemia will depend on your organisation's policies, procedures and the setting. Treatment pathways can also be found on the National Subcutaneous Insulin Chart and the National Subcutaneous Non-Acute Insulin Chart (ACSQHC 2022).

If the person is experiencing symptoms of severe hypoglycaemia, including drowsiness or unconsciousness, immediately call for help and begin emergency treatment according to the person's care plan and the organisation's policies. This is a medical emergency, which, if left untreated, can cause convulsions, irreversible brain damage and death (QLD Health 2023).

If a person carries a hypo kit, they may have glucagon with them. Glucagon, a hormone that rapidly raises blood glucose levels, is used to treat severe hypoglycaemia and is available in an injectable pen device (NDSS 2026).

The hypo kit should also include:

• A blood glucose meter, strips and a lancing device
• Fasting-acting carbohydrates
• Slow-acting carbohydrates

For those experiencing mild hypoglycaemic episodes, it is important to prevent the blood glucose level from dropping further.

Factors affecting treatment will include:

1. Is the person conscious and cooperative?
2. Is the person on an insulin infusion?
3. Is the person nil by mouth or nil by tube?
4. Is the person receiving food orally or by tube?

If the person can tolerate food or medication orally, the treatment will often consist of approximately 15g of fast-acting carbohydrates.

For example:

• 100ml of lucozade
• 6-7 jelly beans
• 125ml (half a glass) of fruit juice, such as orange juice
• 150ml (half a can) of soft drink
• 3 teaspoons of honey
• A sachet of 15g glucose gel
• 15g carbohydrate-containing glucose tablets

(Healthdirect 2024)

This may need to be repeated if the blood glucose level has not risen above 4 mmol/L after 10-15 minutes (Healthdirect 2024).

Once it has stabilised, it is often recommended that the person has a snack or meal with longer-acting carbohydrates such as:

• A glass of milk
• A piece of fruit
• 4 dried apricots
• 1 small tub of yoghurt

(Healthdirect 2024)

Hypoglycaemia in Acute Settings

Hypoglycaemia treatments for patients in hospital will vary depending on the setting and the organisation. It is important to be familiar with your organisation's specific policies and procedures.

Both glucagon injectable devices and oral glucose gel are used in acute settings, as are glucose 10% and glucose 50%, which are administered intravenously. These patients will require close monitoring, with the frequency of blood glucose monitoring dependent on the organisation's policies and procedures.

The Impacts of Hypoglycaemia

A cumulative impact of hypoglycaemia exists that can include:

Societal impacts:

• Loss of driving privileges
• Restricted employment
• Breakdown of family relationships and restricted access to children
• Carer stress and burden
• Additional home-based resources/services or relocation to residential care.

Economic impacts:

• Additional medical care costs
• Time lost from work
• Costs of accidents (road/workplace) occurring as a result of hypoglycaemia.

Impaired awareness of hypoglycaemia as a result of:

• Recurrent hypoglycaemia.
• Autonomic neuropathy
• Long-term diabetes duration
• Altered hormonal counterregulation
• Medication like beta blockers

(Holzen et al. 2024)

Future mortality:

• Severe hypoglycaemia is estimated to be associated with an increased future mortality risk.

Cognitive function:

• Recurrent hypoglycaemia in children may have a lasting impact on cognition as adults
• There is a two-way relationship between dementia and hypoglycaemia in older adults with diabetes.

(Amiel 2021)

It's helpful and useful to acknowledge the fears and concerns people with diabetes have towards hypoglycaemia. Self-management behaviour can change as a result, for example, suboptimal dosing of insulin, overeating and avoiding social situations or sporting activities.

Recurrent hypoglycaemia may lead to fear of hypoglycaemia (FOH), which can impair glycaemic management and quality of life (Przezak, Bielka & Moleda 2022).

Reducing the Risk of Hypoglycaemia

There are several steps a person can take to help prevent hypoglycaemic episodes, including:

• Eating regular meals/snacks and being aware of their carbohydrate content
• Avoiding excess amounts of alcohol, especially without food
• Being aware of incidental activities that can increase the risk of hypoglycaemia, such as exercising, gardening, and shopping for extensive periods
• Being educated about hypoglycaemia, including symptoms, treatment, monitoring and their own action plan
• Carrying a hypo kit at all times
• Wearable technology, if appropriate, such as continuous glucose monitoring with alarm alerts for low BGL
• Checking BGL prior to driving, and being aware not to drive if BGL is lower than 5mmol/L.

(Novo Nordisk Australia 2026; Mathieu 2021)

Conclusion

Recognising and treating hypoglycaemia quickly is critical. The ability to identify symptoms and to act decisively can prevent serious complications. In hospital and community settings alike, awareness of the many risk factors, from insulin prescribing errors and missed meals to lipohypertrophy, helps to anticipate and prevent episodes. Beyond acute management, remember that recurrent hypoglycaemia carries lasting consequences: impaired awareness, fear, and potentially cognitive effects that extend far beyond the episode itself. Supporting people with diabetes to manage their condition with confidence, rather than fear, is central to improving both safety and quality of life.