Subacute hyponatraemia after transurethral resection of the prostate.

We present a case of subacute hyponatraemia which developed 3 days after a transurethral resection of the prostate. Symptoms consisted of nausea, vomiting and headache. Release of vasopressin due to excessive surgical bleeding, combined with liberal oral and intravenous administration of sodium-free fluids, was considered to be the cause.