Review of cases of hyponatraemia in the Port Moresby General Hospital between August 1993 and June 1995.

Hyponatraemia (serum sodium level below 130 mmol/l) is a common electrolyte abnormality in a hospital population. It can be associated with dehydration, overhydration or normal hydration. Clinically, it is important to recognize the common diseases associated with hyponatraemia since correct treatment in terms of fluid replacement is essential in preventing complications of low serum sodium.