Hypoglycemia is a blood glucose level less than 2.5 mmol/L (45 mg/dL).

It may occur in a fasting state or may be post prandial.

Causes of hypoglycemia

  1. Hypoglycemia is commonly iatrogenic
  2. Antidiabetic drugs use
  3. Associated with quinine and salicylates use
  4. After overnight fast
  5. Missed meal(s)
  6.  Exercise
  7. Intensive insulin therapy
  8. May follow weight loss
  9. May follow alcohol ingestion
  10. Reduced insulin clearance
  11. Sepsis
  12. Secondary to non-B cell tumours/insulinoma

Symptoms of hypoglycemia

The two types of hypoglycemic symptoms are neuroglycopenic and neurogenic

1. Neurogenic manifestations of hypoglycemia 

  1. Palpitations
  2. Tremors
  3. Anxiety
  4. Sweating
  5. Hunger
  6. Paresthesia

2. Neuroglycopenic manifestations of hypoglycemia 

  1. Confusion
  2. Fatigue
  3. Seizures
  4. Loss of consciousness
  5. Death

Diagnosis of hypoglycemia

The Whipples’s triad provides a framework for diagnosis of hypoglycaemia:

  1. Symptoms of hypoglycaemia
  2. Alleviation of hypoglycemic symptoms after glucose administration
  3. Low plasma glucose concentration (< 2.5mmole/L)

Differential Diagnoses

  • Other causes of acute confusional state


  • Random blood sugar on presentation
  • Other tests to confirm the cause of hypoglycaemia

Treatment for hypoglycemia


  1. Prompt restoration of normal blood glucose level
  2. Prevention of rebound or recurrent
  3. Prevention of occurrence of neural damage or death


  • Urgent treatment must be given if
    irreversible complications are to be avoided
  • Oral glucose tablets or glucose drinks if tolerated (and if patient is conscious)
  • If there is neuroglycopaenia preventing the use of oral glucose then:

1. Give 50% glucose (dextrose)

  • 50 ml/25 g in double dilution intravenously
  • Followed by 5 – 10% glucose (dextrose) for at least 48 hours in hypoglycaemia secondary to sulphonylurea therapy

2. Glucagon

  • Intravenous glucagon 1mg stat (give
    subcutaneously or intramuscularly if intravenous route is impractical)

Supportive measures

  • Discontinue or reduce the dosage of causative drugs
  • Treat identified underlying cause(s) if any.


  • Glucagon is not effective in glycogen depleted individuals e.g. those with alcohol induced-hypoglycaemia

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