This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Classification of hyponatraemia

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Hyponatraemia can be classified according to the serum sodium concentration:

  • mild - sodium concentration is 125-135 mmol/l

  • moderate - sodium concentration is 115-124 mmol/l

  • severe - sodium concentration is <115 mmol/l

Classification according to volume status:

  • hypovolaemic hyponatraemia
  • euvolaemic hyponatraemia
  • hypervolaemic hyponatraemia (2)

Hyponatraemia is also classified according to the rate of onset (although calculating the duration of hyponatraemia is often difficult):

  • acute hyponatraemia - symptoms develop in less than 48 hours
  • chronic hyponatraemia - symptoms present for more than 48 hours (2,3)


Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page