Excessive loss of hypotonic fluid due to :

• Osmotic diuresis (hyperglycemia,...).
• Loop diuretics.
• Dehydration due to extrarenal water loss (diarrhea, vomiting, sweating) or drinking too little water.
• Diabetes insipidus.

1. Reduction or discontinuation of diuretics, especially in the case of signs of dehydration or if there are no signs of fluid retention.
2. Administration of more water, hypotonic fluid:

• Drinking more water.
• If necessary, a slow subcutaneous or intravenous infusion with glucose 5%, for example 1 liter at 40 to 80 ml per hour.

Note: during this treatment, monitor the sodium level and glycaemia closely. Hypernatremia must not be corrected too slowly or too quickly :

• Too slow correction of acute hypernatremia: risk of thrombosis, hemorrhage or osmotic demyelination.
• Too rapid correction of chronic hypernatremia: risk of cerebral oedema and brain damage (e.g. in case of uncontrolled diabetes mellitus).