Diabetes & Hyperglycaemic Emergencies
Integrate diagnosis and complication prevention with safe recognition of hypoglycaemia, ketoacidosis and hyperosmolar illness.
Quick revision ↓ Medical Dictionary
01Diagnose in context
Use accepted plasma glucose or HbA1c criteria with confirmation when required, considering symptoms and conditions that make HbA1c unreliable. Do not assume an adult cannot have type 1 diabetes. Weight loss, ketosis and rapid deterioration require urgent assessment. Long-term care includes cardiovascular and kidney risk, feet, eyes and education rather than focusing only on a glycaemic number. Targets should reflect comorbidity, hypoglycaemia risk and patient circumstances.
02Recognise hypoglycaemia
Sweating, tremor, palpitations, behavioural change, confusion or seizures can reflect low glucose. Check promptly and treat through the emergency pathway, using oral carbohydrate only when swallowing is safe. Reduced consciousness needs a non-oral approach and help. Recheck glucose and identify the cause, including missed food, insulin, sulfonylureas, alcohol or kidney impairment. Recurrence can occur after initial recovery, especially with longer-acting medicines.
03Identify DKA and HHS
DKA involves ketonaemia and metabolic acidosis in the context of diabetes or hyperglycaemia; glucose can be less striking with SGLT2 inhibitors. HHS involves marked hyperglycaemia and hyperosmolality with major water deficit, often without the same degree of ketoacidosis. Overlap occurs. Assess volume, consciousness, ketones, electrolytes, renal function and the precipitant rather than deciding severity from glucose alone.
04Monitor treatment closely
Hyperglycaemic emergencies require a protocol-led hospital plan for fluids, insulin, potassium and frequent reassessment. Total body potassium can be depleted despite a normal or high initial serum level. Insulin lowers extracellular potassium, so significant hypokalaemia must be addressed before insulin according to protocol. Avoid overly rapid osmotic shifts, particularly in HHS. Track resolution of the metabolic disorder rather than stopping care as soon as glucose falls.
05Prevent recurrence
Seek infection, missed insulin, new illness and barriers to supplies or understanding. Explain sick-day guidance, ketone testing where appropriate and when to seek urgent help. Patients using insulin need individual advice rather than stopping it automatically when eating less. Review technique, access, follow-up and the reason for the episode. A non-judgemental discussion is more likely to reveal practical causes than labelling the patient noncompliant.
DKA and HHS • Recognise the dominant problem
| Feature | DKA | HHS |
|---|---|---|
| Dominant disturbance | Ketonaemia and metabolic acidosis | Marked hyperosmolality and water deficit |
| Glucose | Can be less elevated, including with SGLT2 inhibitors | Usually markedly elevated |
| Monitoring priorities | Ketones, pH, glucose, potassium and fluid status | Osmolality, glucose, electrolytes, consciousness and fluid status |
High-Yield Revision
- Hypoglycaemia can mimic stroke or cause altered behaviour.
- DKA can occur without extreme glucose elevation.
- Potassium and fluid monitoring are central to emergency treatment.
Common Pitfalls
- Never give oral carbohydrate to someone unable to swallow safely.
- Do not equate a falling glucose with complete resolution of DKA.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 27 September 2026. Consult current local protocols for prescribing, procedures and escalation.