Hypoglycaemia

General Medicine

Plasma glucose <70 mg/dL (3.9 mmol/L) with autonomic / neuroglycopenic symptoms (Whipple's triad).

Etiology

  • • Insulin / sulfonylurea overdose
  • • Missed meal, exercise, alcohol
  • • Adrenal insufficiency, sepsis, liver failure
  • • Insulinoma (rare)

History taking

  • • Drug timing, meals, exercise
  • • Awareness of hypoglycaemia
  • • Recurrent episodes

Examination

  • • General: vitals, pallor, icterus, oedema, lymphadenopathy
  • • Focused system examination
  • • Look for red-flag findings

Red flags

  • • Loss of consciousness, seizure
  • • Persistent neurological deficit

Differential diagnosis

  • • See differentials section per chief complaint

Recommended investigations

  • • CBC, basic metabolic panel as indicated
  • • Targeted disease-specific tests

Diagnosis

  • • Clinical diagnosis supported by targeted investigations

Initial treatment / management

  • • Conscious: 15 g fast carbs (glucose tabs / juice), recheck in 15 min
  • • Unconscious: IV dextrose 25 g or IM glucagon 1 mg

Drug therapy

  • • Identify and stop offending drug
  • • Adjust insulin / OHA

Follow-up advice

  • • Review in 2–4 weeks or earlier if worsening
  • • Monitor response to therapy and adverse effects

Patient counselling

  • • Carry glucose source
  • • Educate family on glucagon
  • • Inform DVLA / equivalent if recurrent

Referral criteria

  • • Refer if diagnostic uncertainty, complications, or failure of first-line therapy

Clinical pearls

  • • Sulfonylurea hypoglycaemia can recur for 24–72 h — admit

References

  • • Harrison's Principles of Internal Medicine, 21e
  • • NICE / WHO guidelines (current edition)

Educational outpatient guide — verify against local guidelines before clinical use.

WardRound

WardRound

Clinical Decisions in Seconds