Table 1

 Causes of hypernatraemia

Water depletionSodium excess
• Inadequate intake Lack of access to water• Inappropriate intravenous therapy
    Inadequate breast feeding Sodium bicarbonate
    Unconscious/mentally impaired Hypertonic saline
    Adipsia (lack of thirst perception)
• Increased renal loss Central diabetes insipidus• Salt poisoning/overload Accidental
    “Nephrogenic” diabetes insipidus  Salt used as an emetic
    Renal medullary damage  Faulty feed preparation
• Increased gastrointestinal loss Non-accidental
    Hypertonic dehydration  Salt as a punishment
• Increased evaporative loss  Deliberate poisoning
    Lost in the desert/ocean
• Essential hypernatraemia