Assess severity of hyponatraemia

It would be unusual to develop symptomatic hyponatraemia with a sodium of >125.

Most people tolerate longstanding hyponatraemia well. Symptoms normally only develop if there is a rapid change in sodium level (>5-10mmol in 48h).

Vomiting, headaches, reduced GCS, coma and seizures can all be symptoms of severe hyponatraemia.

*please note that there are MANY causes of these symptoms – ensure you have fully assessed the patient for concurrent pathology*