Hypernatraemia
Severity
Range
- MildNa 146–150
- ModerateNa 151–159
- SevereNa ≥ 160 or symptomatic
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Water loss — renal Causes
Diabetes insipidus (cranial / nephrogenic)Osmotic diuresis (hyperglycaemia, mannitol)Loop diuretics
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Water loss — extra-renal Causes
GI losses (diarrhoea, vomiting)Sweating, burns, feverInadequate intake (frail elderly, dementia)
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Na+ gain Causes
Hypertonic salineSodium bicarbonateSalt poisoning (rare)Conn's syndrome