Hyperglycaemia: A Diabetes Emergency

Hyperglycaemia is a condition in which a person has an abnormally high level of glucose in their bloodstream. Generally, a blood glucose level (BGL) above 15 mmol/L is considered hyperglycaemia (Healthdirect 2024).

What is Hyperglycaemia?

Hyperglycaemia can be defined as blood glucose levels greater than 7.0 mmol/L when fasting or greater than 10 mmol/L two hours after eating (RACGP 2026).

Hyperglycaemia can be triggered by:

• Sickness
• Infection
• Injury or surgery
• Stress
• Inactivity
• Excess carbohydrate intake
• Insufficient or ineffective (e.g. expired) or omission of insulin or diabetes medicines
• Incorrect insulin administration technique
• Other medicines such as corticosteroids and some antipsychotics.

(RACGP 2026; Battocchio 2022; Healthdirect 2024)

Signs and Symptoms of Hyperglycaemia

Hyperglycaemia can result in clinical symptoms that include:

• Lethargy
• Polyuria (excessive urine)
• Polydipsia (excessive thirst)
• Polyphagia (excessive hunger)
• Weight loss (more commonly seen with type 1 diabetes).

Other clinical features can include:

• Frequent fungal or bacterial infections
• Poor wound healing
• Blurred vision
• Loss of sensation (i.e. touch, vibration, cold)
• Dry skin and boils
• Worsening of urinary incontinence (in older people)
• Clinical signs of dehydration
• Poor memory and concentration.

(RACGP 2026)

Hyperglycaemia can evolve into medical emergencies that require urgent assessment and management. Prompt treatment of hyperglycaemia is essential, as persistently high glucose levels can affect vital organs, including the kidneys, eyes and nerves (Battocchio 2022).

Who is at Risk of Hyperglycaemia?

The following factors increase the risk of hyperglycaemia:

• Type 1 diabetes, especially in younger and older people
• Illness, infection or psychological stress
• Pregnancy
• Inadequate doses of diabetes medication, including insulin
• Expired insulin or poor injection technique
• Eating disorders
• Comorbidities, including kidney disease, depression, pancreatitis, pulmonary embolisms, neuropathy, and stroke
• Insulin pump malfunctions
• Previous or recurrent hyperglycaemia
• Smoking, alcohol or recreational drug consumption.

(RACGP 2026; Umpierrez et al. 2024; Battocchio 2022)

Types of Hyperglycaemia Emergencies

A blood glucose level >15 mmol/L on two subsequent occasions, two hours apart, with clinical symptoms of metabolic disturbance should be considered a hyperglycaemic emergency requiring assessment and intervention (RACGP 2026).

Hyperglycaemia emergencies fall into two distinct categories: diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic state (HHS) – extreme manifestations of impaired carbohydrate regulation that can occur in people with diabetes (RACGP 2026).

1. Diabetic Ketoacidosis (DKA)

Diabetic ketoacidosis (DKA) is a life-threatening complication in patients with untreated or mismanaged diabetes.

DKA occurs when excessive amounts of ketone – a type of acid that in large amounts is toxic to the body – are released into the bloodstream as a result of the body breaking down lipids, instead of utilising glucose as the energy source (Hamdy & Khardori 2024; NDSS 2024).

This process is known as gluconeogenesis and occurs when the body lacks sufficient insulin to allow glucose to be taken up from the bloodstream into cells (Hamdy & Khardori 2024).

Common causes of DKA include infection, surgery, a new illness, missed insulin doses, incorrect insulin dosing, expired insulin, insulin pump malfunctions, and improper storage (Healthdirect Australia 2024). It is also a rare but possible side effect of SGLT2 inhibitor medicines (Healthdirect Australia 2024).

Possible symptoms of a hyperglycaemic crisis associated with DKA include:

• Extreme thirst
• Nausea and/or vomiting
• Abdominal pain
• Polyuria
• Sudden weight loss
• Severe fatigue
• Altered state of consciousness, including coma
• Ketotic breath (may smell fruity or like acetone)
• Increased respiratory rate (known as Kussmaul breathing)
• Dehydration.

(RACGP 2026; Lizzo, Goyal & Gupta V 2022)

Euglycaemic DKA (EDKA)

Euglycaemic DKA (EDKA) is a medical emergency characterised by severe metabolic acidosis and high blood ketones despite having normal or mildly elevated blood glucose levels (Chow, Clement & Garg 2023). It meets all other biochemical criteria for DKA despite the absence of significant hyperglycaemia.

Symptoms of EDKA can include vomiting, fatigue, shortness of breath, tachycardia and abdominal pain. Since EDKA lacks the marked elevation in BGL typically seen in DKA, clinicians face a diagnostic dilemma. Patients and clinicians may be misled by relatively normal or only mildly elevated point-of-care glucose testing and prematurely rule out a metabolic cause for their symptoms (Chow, Clement & Garg 2023).

Like DKA, contributing factors for EDKA also include SGLT2 inhibitors, infection, sepsis, excessive alcohol intake, recent surgery, extremely low-carbohydrate or ketogenic diets, insulin pump failure, prolonged fasting and more (Chow, Clement & Garg 2023).

SGLT2 inhibitor management: To reduce the risk of DKA for inpatients, the Australian Diabetes Society recommends that SGLT2 inhibitors be omitted for three days pre-procedure (two days prior to surgery, and on the day of surgery/procedure). The treating team may decide to increase the doses of other glucose-lowering drugs during that time. The treating medical team must document the plan clearly to be followed during the patient's admission. You should flag and escalate when unsure of the plan, and never omit, reduce, increase or administer the medication without clarification (ADS 2022).

2. Hyperosmolar Hyperglycaemic State (HHS)

Persistent hyperglycaemia (with an approximate BGL of 25 mmol/L) with absent or minimal ketoacidosis is known as a hyperosmolar hyperglycaemic state (HHS). It is commonly accompanied by hyperosmolality, dehydration and fluctuation in mental state (RACGP 2026). HHS is more common in older people and those newly diagnosed with type 2 diabetes (RACGP 2026).

Possible symptoms of a hyperglycaemic crisis associated with HHS include:

• Atypical symptoms, including pain and fever
• Non-specific symptoms such as headache, weakness, malaise and lethargy
• Vomiting and abdominal pain
• Dry mouth and thirst
• Cool extremities and rapid pulse
• Delayed capillary refill
• Extreme dehydration
• Reduced urination (oliguria) that may progress to anuria
• Decreased skin turgor
• Altered state of consciousness, including coma.

(RACGP 2026; Adeyinka & Kondamudi 2023)

Assessing for Hyperglycaemia

A clinical assessment may include the following:

• Blood glucose and blood ketone levels
• Temperature checks
• Blood pressure monitoring
• Heart rate monitoring
• Respiratory rate monitoring
• Neurological assessments such as the Glasgow Coma Scale
• Urgent point-of-care assessment.

(RACGP 2026; Adeyinka & Kondamudi 2023)

The biochemical criteria for DKA are:

• BGL >11 mmol/L
• Venous pH <7.3 or bicarbonate <15 mmol/L
• Presence of blood ketones or urinary ketones (an abnormal blood ketone level is ≥0.6 mmol/L; severe ketosis is >3.0 mmol/L).

(RACGP 2026)

Treating Hyperglycaemic Emergencies

DKA and HHS must be managed within the hospital setting. Emergency Management Clinical Pathways for adults and children have been developed to assist clinicians from presentation through discharge. These inpatient protocols outline investigations, fluid replacement, insulin administration, and other actions required throughout the admission and may differ slightly across health services (Queensland Health 2023; Children's Health Queensland 2024). You must follow your organisation's specific policies and procedures, as well as the treatment plan for the person.

Preventing Hyperglycaemia

Inadequate insulin treatment (including non-compliance) and infection are the two major precipitating factors in the development of DKA (Hamdy & Khardori 2024).

In many cases, these events may be prevented by:

• Better access to medical care
• Intensive patient education
• Effective communication with a healthcare provider during acute illnesses.

(Gosmanov & Nematollahi 2023)

It's vital that people with diabetes have a sick day plan and management kit to provide information on managing their diabetes while unwell (Diabetes Australia 2024). Credentialled diabetes educators can assist in formulating individual sick day plans for people with type 1 and 2 diabetes and those who are planning to be or are currently pregnant. These sick day plans should be reviewed and updated regularly, especially after an episode of illness. Sick day kits are also a vital part of travel planning (ADEA 2020).

Hyperglycaemic Emergencies in Children and Adolescents

It should be noted that separate guidelines and clinical pathways exist for children who develop DKA and HHS (Children's Health Queensland 2024) and to assist clinicians in the early recognition of hyperglycaemia in children aged under 16 years (Queensland Health 2023). Always refer to your organisation's specific guidelines and policies.

Conclusion

Hyperglycaemia requires prompt recognition and intervention to prevent serious complications. DKA and HHS states are life-threatening emergencies requiring hospital-based management, at times preventable through patient education and individualised sick day plans (Gosmanov & Nematollahi 2023). Clinicians must follow their organisation's specific policies, procedures and clinical pathways when managing hyperglycaemia. The treating team should clearly document the management plan, and you should escalate any uncertainties regarding the care approach.