Hypernatremia

An abnormally elevated serum sodium concentration (>145 mmol/L), usually reflecting a deficit of free water relative to total body sodium and leading to cellular dehydration, particularly affecting the central nervous system.

Causes

• Reduced water intake

• Excessive water loss/dehydration

  • Fever

  • Tachypnea or increased respiratory water loss

  • Diarrhea

  • Vomiting

  • Hyperhidrosis

  • Burns

  • Polyuria

• Diabetes insipidus (central or nephrogenic)

• Medications: Diuretics, Lithium

• Excessive salt intake: Salty diet, intravenous NaCl

• Iatrogenic fluid management errors