In February 2026 new BNSSG consensus guidelines for Hyponatraemia were published. Which can be found via this link.
Please note, before this there were 2 different guidelines, that documented different reference ranges for mild, moderate and severe hyponatraemia. The consensus guideline now documents more conservative (higher Sodium levels) levels as 'mild', 'moderate' and 'profound'. As has always been the case the chronicity of the low sodium level and the patient's clinical status are also paramount in making a safe clinical plan.
If you need advice on interpretation or management of hyponatraemia, information about the duty biochemist is available here.