Hyperglycaemia: A Diabetes Emergency


Published: 07 August 2022

What is Hyperglycaemia?

Hyperglycaemia is a condition in which a person presents with an abnormally high level of glucose circulating in their bloodstream (Better Health Channel 2014).

Blood glucose levels can rise above target quickly or slowly over time. In the latter, people often do not experience any symptoms until their blood glucose levels reach an extremely high level (Diabetes Australia 2021).

Hyperglycaemia can generally be defined as:

  • Blood glucose level > 7.0 mmol/L (126 mg/dl) when fasting
  • Blood glucose level > 11.1 mmol/L (200 mg/dl) two hours after meals.

(Diabetes.co.uk 2022)

hyperglycaemia diagram

The Australian Diabetes Society (2012) recommends that most patients admitted with accompanying hyperglycaemia should be treated to achieve and maintain glucose levels less than 10.0mmol/L.

For people with diabetes who wear continuous glucose monitoring sensors, glycaemic targets can be measured using detailed generated 14 day ambulatory glucose profile reports (Battelino et al. 2019).

Glucose ranges Targets [% of readings (time/day)]
Greater 13.9mmol/L Less than 5% (1 hour, 12 minutes)
10.0 – 13.9mmol/L Less than 25% (6 hours)
Time in range 3.9 – 10.0mmo/L Greater than 70% (16 hours, 48 minutes)
Less than 3.9mmol/L Less than 4% (58 minutes)
Less than 3.0mmol/L Less than 1% (14 minutes)

(Battelino et al. 2019)

These targets will vary with different cohorts of people with diabetes, including different types of diabetes, ages and pregnancy (Battelino et al. 2019).

Raised HbA1c results (three month glucose average) is also indicative of hyperglycaemia. For example, the estimated glucose average of a suboptimal HbA1c result of 8% is 10.1mmol/L and 10% is 13.4mmol/L (ADA 2019).

What Causes Hyperglycaemia?

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
  • Illicit drug use.

(Diabetes Australia 2021; Battocchio 2022)

Signs and Symptoms of Hyperglycaemia

Hyperglycaemia can result in clinical symptoms that include:

  • Lethargy
  • Polyuria
  • Polydipsia
  • 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, boils
  • Worsening of urinary incontinence (in older people)
  • Clinical signs of dehydration.

Such symptoms may be similar to those that occurred when diabetes was originally diagnosed. (RACGP 2020).

What are the Risks of Hyperglycaemia?

Prompt treatment of hyperglycaemia is essential, as regularly having high levels of glucose can affect vital organs including the kidneys, eyes and nerves (Better Health Channel 2014). Raised blood glucose levels can impact on physical energy, which in turn can impact on mental wellbeing.

Hyperglycaemia can evolve into medical emergencies that require urgent assessment and management to reduce preventable morbidity. They may present as the first indication of diabetes in undiagnosed people, or as a crisis for those with known diabetes (RACGP & ADS 2018).

Types of Hyperglycaemia Emergencies

hyperglycaemia emergency 15.3 mmol/L

A blood glucose level of >15mmol/L on two subsequent occasions, two hours apart, with the clinical symptoms of metabolic disturbance should be considered a hyperglycaemic emergency that requires assessment and intervention (RACGP 2020).

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.

Both DKA and HHS are classified as emergencies. However, mortality is higher in HHS than in DKA - as it often relates to a precipitating condition in an older person (RACGP & ADS 2018).

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 (Reading 2016; Hamdy & Khardori 2021; NDSS 2019).

This process is known as gluconeogenesis and occurs when the body does not have sufficient insulin to allow the uptake of glucose from the bloodstream into the cells. It’s observed primarily in people with type 1 diabetes but it can occur in type 2 diabetes under certain circumstances (Reading 2016; Lizzo et al. 2022).

DKA is more common in younger people, and is seen more in females than in males (Cedars-Sinai 2019).

DKA can cause rapid deterioration and an altered state of consciousness (RACGP & ADS 2018).

Possible symptoms of a hyperglycaemic crisis associated with DKA include:

  • Extreme thirst
  • Extreme fatigue
  • Nausea and or vomiting
  • Abdominal pain
  • Increased susceptibility to oral thrush or yeast infection
  • Constant urination
  • Weight loss
  • Altered state of consciousness
  • Ketotic breath (may smell fruity or like acetone)
  • Increased respiratory rate (known as Kussmaul breathing)
  • Dehydration
  • Blurred vision.

(RACGP & ADS 2018; RCN 2021; Better Health Channel 2014)

2. Hyperosmolar Hyperglycaemic States (HHS) - Formerly Known as Hyperosmolar Non-Ketotic Coma (HONC)

Persistent hyperglycaemia in the absence of ketosis is known as hyperosmolar hyperglycaemia state (HHS). HHS is accompanied by intense dehydration (RACGP & ADS 2018).

HHS is more closely associated with type 2 diabetes and typically affects older patients (RACGP & ADS 2018).

HHS is common in patients who:

  • Have acute sepsis
  • Have just experienced a cardiovascular event
  • Have renal dysfunction.

(RACGP & ADS 2018)

Coma may develop in some patients (RACGP & ADS 2018).

Possible symptoms of a hyperglycaemic crisis associated with HHS include:

  • Atypical symptoms including:
    • Pain
    • Fever
  • Non-specific symptoms (in children), such as:
    • Headache
    • Weakness
    • Vomiting
    • Abdominal pain
  • Dry mouth
  • Thirst
  • Cool extremities
  • Rapid pulse
  • Extreme dehydration
  • Reduced urination (oliguria) that may progress to anuria
  • Decreased skin turgor
  • Altered state of consciousness.

(RACGP & ADS 2018; Stoner 2017)

Who is at Risk of Hyperglycaemia?

hyperglycaemia risk factor omitting insulin

People who fall into the following categories should be closely monitored:

  • Those who are pregnant (pregnancy is a ketogenic state and hypoglycemia can occur due to illness, inadequate dietary intake or insulin dosing at lower glucose levels)
  • Children and young people with type 1 diabetes - especially those young people transitioning to adult services
  • Those who have unstable glycaemic control
  • Those omitting diabetes-related medication, especially insulin
  • People with type 1 diabetes and disordered eating such as diabulimia
  • Those who use an insulin pump (pump malfunctions can result in rapidly rising blood glucose levels due to the use of rapid-acting insulin - there is no long-acting or basal insulin in use)
  • Previous or recurrent DKA
  • Those with pancreatitis
  • Those who have experienced:
  • Those with high-rates of alcohol or recreational drug consumption
  • Older adults
  • Those taking certain medications such as corticosteroids, atypical antipsychotics and immunosuppressive agents.

(RACGP & ADS 2018; Rudland et al. 2020; Suo Ying Nip & Lodish 2021; NDSS 2021)

Assessing for Hyperglycaemia

A clinical assessment may include the following:

  • Blood glucose and blood ketone levels (blood ketone testing is preferred to urine testing)
  • 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 & ADS 2018)

The biochemical criteria for DKA is:

  • The ‘D’ - blood glucose >11mmol/L
  • The ‘K’ - presence of blood ketone levels ≥0.6mmol/L and >3.0mmol/L in severe ketosis
  • The ‘A’ - venous pH <7.3 or bicarbonate <15mmol/L.

(RACGP 2020; JBDS-IP 2021)

Treating Hyperglycemic Emergencies

Hyperglycaemia 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 the time of presentation until discharge. These inpatient protocols outline investigations, fluid replacement, insulin administration and other actions required throughout the admission and may differ slightly between various health services (Queensland Government 2015; Children’s Health Queensland Hospital and Health Service 2021).

Preventing Hyperglycaemia

preventing hyperglycaemia patient education

Inadequate insulin treatment (and noncompliance) and infection are the two major precipitating factors in the development of DKA (Hamdy & Khardori 2021).

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 2022)

An educational program should be provided to review illness management with direct information on the administration of short-acting insulin, including frequency of insulin administration, blood glucose goals during illness, methods to suppress fever and treat infection, and initiation of an easily digestible liquid diet containing carbohydrates and salt (Kitabchi et al. 2001). A key content area of diabetes self-management and education support pertains to the prevention of acute complications such as DKA for insulin pump users (Holt et al. 2021).

It’s crucial to note that the patient should never discontinue insulin and must seek professional advice early in the course of the illness (Kitabchi et al. 2001; Better Health Channel 2014). 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 2022). 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 regularly reviewed and updated especially following an episode of illness. Sick day kits are also a vital part of travel planning (ADEA 2020).

People who present with recurrent DKA may be experiencing fragmented care, or social, behavioural or psychological issues. Other risk factors for recurrent DKA can include gender (female), adolescence and low socioeconomic status (JBDS-IP 2021).

Euglycaemic DKA

Euglycaemic DKA is defined as mild or moderate blood glucose elevation (>11.1mmol/L) with all other biochemistry criteria for DKA. This can occur in people prescribed SGLT2 inhibitors, people who are pregnant, following excessive alcohol intake, post-surgery/colonoscopy, or in people on extremely low carbohydrate diets. In order to reduce the risk for inpatients, the Australian Diabetes Society’s updated position statement outlines that SGLT2 inhibitors should be omitted for three days pre-procedure (two days prior to surgery and on the day of surgery/procedure) (ADS 2022).

Hyperglycaemic Emergencies in Children and Adolescents

It should be noted that separate guidelines and clinical pathway exist for children who develop DKA and HHS (Children’s Health Queensland Hospital and Health Service 2021) and to assist clinicians in the early recognition of hyperglycaemia in children aged under 16 years (Queensland Health 2021).


Test Your Knowledge

Question 1 of 3

True or false: Excessive thirst is a symptom of diabetic ketoacidosis.


educator profile image
Michelle Robins View profile
Michelle Robins is a credentialled diabetes educator and a nurse practitioner with Northern Health. She has worked for 30 years as a diabetes educator at several major tertiary hospitals in Victoria and Queensland. Michelle has served on more than 50 diabetes-related committees and contributed to book chapters on diabetes.
educator profile image
Ausmed View profile
Ausmed’s editorial team is committed to providing high-quality, well-researched and reputable education to our users, free of any commercial bias or conflict of interest. All education produced by Ausmed is developed in consultation with healthcare professionals and undergoes a rigorous review process to ensure the relevancy of all healthcare information and updates to changes in practice. If you have identified an issue with the education offered by Ausmed or wish to submit feedback to Ausmed's editorial team, please email ausmed@ausmed.com.au with your concerns.