Hyperglycaemia - a fasting blood glucose above 7 mmol/L (126 mg/dL) is a daily reality for many people with diabetes in India. Mild to moderate elevation responds to adjustment of food, activity or medication. Left uncorrected for too long, or driven very high by illness, missed insulin or a medical crisis, blood glucose can reach genuinely life-threatening levels. The two most dangerous hyperglycaemic emergencies are DKA (diabetic ketoacidosis, primarily in type 1 diabetes) and HHS (hyperosmolar hyperglycaemic state, primarily in type 2 diabetes). Both require urgent hospital treatment.

What Is Hyperglycaemia?

Hyperglycaemia occurs when blood glucose rises above the level at which the body can regulate it safely, causing a cascade of metabolic and physiological effects. In diabetic ketoacidosis, insufficient insulin forces the body to break down fat for energy; ketone bodies accumulate as by-products and acidify the blood, producing metabolic acidosis. Whereas hyperosmolar hyperglycaemic state (HHS) produces a different pattern: enough insulin prevents ketone formation but glucose climbs to extreme levels drawing water out of cells and causing profound dehydration & dangerously high blood concentration.

Both emergencies cause severe cellular dehydration and electrolyte disturbance; DKA requires insulin to correct the acid-base disturbance as the primary goal while HHS requires cautious fluid replacement over 24 to 48 hours to avoid cerebral oedema from rapid fluid shifts.

Common Causes of Hyperglycaemia

A trigger is identifiable in most severe cases, and finding it is as important as treating the high glucose itself. Common causes are:

Missed or insufficient insulin doses are the most common precipitant of DKA in type 1 diabetes even a single missed dose can initiate ketosis within hours in someone with no residual pancreatic function.
Concurrent infection like urinary tract infection, pneumonia or gastroenteritis dramatically raises insulin requirements in both types of diabetes frequently precipitating hyperglycaemic crises in previously well-controlled patients.
Newly diagnosed type 1 diabetes often presents first with DKA, when the underlying diagnosis has not yet been made and the person has been hyperglycaemic for days to weeks.
In type 2 diabetes, HHS is most commonly triggered by severe illness, inadequate fluid intake, hyperglycaemia-inducing medications such as steroids or certain antipsychotics, or prolonged poor diabetes control.
Myocardial infarction, stroke, and other acute medical events cause a profound stress response that elevates blood glucose and sometimes triggers a hyperglycaemic emergency as the first presentation of underlying diabetes.

Signs and Symptoms of Hyperglycaemia

Symptoms build gradually in moderate hyperglycaemia but can develop rapidly as glucose climbs into the emergency range. They are:

Polyuria (large, frequent volumes of urine) and polydipsia (intense, unquenchable thirst) are the earliest warning signs as the kidneys work to excrete excess glucose in the urine.
Nausea, vomiting and abdominal pain alongside high blood glucose strongly suggest DKA.
Kussmaul breathing - deep, rapid respirations with a faint acetone smell (fruity or nail-varnish-like) is the physiological response to the metabolic acidosis of DKA.
Progressive drowsiness, confusion and coma are more characteristic of HHS than DKA; extreme blood hyperosmolality causes neuronal dysfunction at very high glucose levels.
Tachycardia, hypotension, and dry mucous membranes reflect the severe dehydration common to both emergencies and signal that urgent fluid replacement is needed.

First Aid for Hyperglycaemia (Before Reaching Hospital)

Severe hyperglycaemia cannot be safely managed at home the priority is emergency care. You should:

Call emergency services immediately if the person is vomiting repeatedly, confused, very drowsy, breathing rapidly and deeply or has a blood glucose reading above 360 mg/dL that is not falling.
A person who is alert, not vomiting and has mild to moderate hyperglycaemia should drink water or sugar-free fluids, take prescribed rapid-acting insulin and recheck glucose within one to two hours.
Do not give food or sugary drinks to someone with high blood glucose; plain water is the appropriate fluid until medical assessment.
Note the last insulin dose, current blood glucose reading, and any recent illness or dietary changes as this information directly guides emergency management.

When to Seek Emergency Care for Hyperglycaemia

Specific thresholds and clinical features signal that home management is no longer appropriate. They are:

A blood glucose reading above 20 mmol/L (360 mg/dL) that does not respond to an insulin correction dose within two hours
Moderate or large ketones on a urine dipstick or blood ketones above 3 mmol/L
Vomiting, drowsiness, confusion, deep rapid breathing or abdominal pain alongside high blood glucose
Insulin pump users who develop pump failure or site problems should seek emergency assessment promptly as DKA can develop within hours without delivered insulin.

Emergency Treatment at the Hospital for Hyperglycaemia

Hospital treatment is protocol-driven and addresses glucose, fluids and electrolytes simultaneously.

Intravenous insulin infusion (a continuous low-dose insulin drip rather than large bolus doses) lowers blood glucose at a controlled, safe rate in DKA. Too-rapid correction causes dangerous hypoglycaemia and cerebral oedema, particularly in children.
Intravenous fluid resuscitation addresses the very large deficits typical of both conditions.
Potassium replacement is critical in DKA: insulin drives potassium from blood into cells and without concurrent supplementation, life-threatening hypokalaemia develops rapidly.
The precipitating cause is treated in parallel: antibiotics for infection, management of myocardial infarction where indicated and review of the diabetes regimen before discharge to reduce recurrence risk.

Conclusion

Hyperglycaemic emergencies are largely preventable but when they occur, they need hospital treatment rather than home remedies. DKA and HHS are both serious: DKA carries a high life threatening risk if acidosis is not corrected. Vomiting, deep breathing, confusion, ketones in the urine or a glucose reading that will not respond should always prompt an emergency call rather than further home treatment.

FAQs

1. When should I seek emergency care for hyperglycaemia?

Seek emergency care if blood glucose exceeds 20 mmol/L and does not fall after a correction dose, if ketones are moderate or large or if vomiting, confusion, deep rapid breathing, or abdominal pain accompany the high glucose.

2. What blood sugar level is considered a medical emergency?

A glucose reading above 20 mmol/L (360 mg/dL) not responding to treatment, or any glucose level accompanied by ketones, vomiting, confusion or rapid deep breathing, are a medical emergency.

3. What should I do if my blood sugar remains very high?

Drink plain water, take a prescribed rapid-acting insulin correction dose if trained to do so, recheck glucose within one to two hours and call emergency services if the level stays very high, ketones are present or any symptoms develop.

4. Can missing insulin lead to a hyperglycaemic emergency?

Yes in type 1 diabetes, a single missed dose can initiate ketosis within hours. Within 12 to 24 hours without insulin full DKA develops, which is why insulin must never be stopped without medical guidance.

5. Can hyperglycaemia cause dehydration?

Yes excess glucose draws water from tissues and is excreted in large volumes of urine, causing osmotic dehydration.

6. What emergency tests are performed for hyperglycaemia?

Blood glucose, blood ketones (or urine ketone dipstick), blood gas for pH and bicarbonate, electrolytes, kidney function, full blood count and ECG to assess potassium effects on heart rhythm.

7. What treatments are available for severe hyperglycaemia?

Intravenous insulin infusion to correct acidosis in DKA, fluid resuscitation for both DKA and HHS, potassium replacement to prevent hypokalaemia and treatment of the precipitating cause are the main interventions.

8. Can hyperglycaemia affect the kidneys?

Yes, in the short term osmotic diuresis causes acute kidney injury through dehydration. Whereas in the long term persistently elevated glucose damages the glomeruli (filtering units) and causes diabetic nephropathy over years.

9. What complications can occur if severe hyperglycaemia is left untreated?

Left untreated severe hyperglycaemia can progress to diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic state (HHS), both of which require emergency care. It can also cause severe dehydration, electrolyte imbalances and kidney damage. In advanced cases, patients can slip into a coma, and delayed treatment can lead to lasting organ damage or prove fatal.

10. How long does recovery from a hyperglycaemic emergency take?

Most DKA episodes resolve with 12 to 24 hours of intravenous treatment and discharge within two to three days. HHS typically takes three to five days to correct safely.

11. When should I follow up with my doctor after emergency treatment for hyperglycaemia?

A diabetes clinic review within one week of discharge is standard to assess the precipitating cause, adjust the insulin or medication regimen, and reduce the risk of a further episode.