Diabetes

Hypoglycaemia: Symptoms & Treatment

Hypoglycaemia (low blood sugar) can develop rapidly and cause confusion, seizures, or loss of consciousness if not treated promptly — recognising early symptoms is essential.

Threshold
<4.0 mmol/L (70 mg/dL)
Severe hypo
<3.0 mmol/L, needing assistance
Fast treatment
15-20g fast-acting carbohydrate
Most common in
Insulin-treated diabetics

Warning Symptoms

StageSymptoms
Early (autonomic)Shaking, sweating, hunger, rapid heartbeat, anxiety
Later (neuroglycopenic)Confusion, slurred speech, poor coordination, unusual behaviour
SevereSeizures, loss of consciousness — medical emergency

The 15-15 Rule for Treatment

  1. Take 15g fast-acting carbohydrate (4 glucose tablets, small glass of juice, or 3 teaspoons of sugar)
  2. Wait 15 minutes
  3. Recheck blood glucose
  4. If still low, repeat
  5. Once blood glucose recovers, eat a longer-acting carbohydrate (sandwich, biscuits) to prevent recurrence

Causes in People With Diabetes

Severe Hypoglycaemia — EmergencyIf someone is unconscious or unable to swallow safely due to low blood sugar, do NOT give food or drink by mouth (choking risk) — call 999 and, if trained and available, give glucagon injection or nasal glucagon.
Hypoglycaemia Unawareness — A Dangerous ComplicationSome people with long-standing diabetes lose the ability to sense early warning symptoms of hypoglycaemia ('hypo unawareness'), making severe episodes more likely — continuous glucose monitors can help detect drops before symptoms would normally appear.
Can non-diabetics have hypoglycaemia?
Yes, though less commonly — causes include reactive hypoglycaemia (after meals), certain medications, alcohol, hormone deficiencies (Addison's disease), and rarely, insulin-producing tumours (insulinoma).
Why shouldn't I give chocolate for a hypo?
Chocolate contains fat, which slows sugar absorption — pure glucose sources (tablets, juice, sugar) work faster and are preferred for rapid treatment of hypoglycaemia.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.