The authors present a case-review of a posttraumatic syndrome with natrium ions and water wasting, resulting in hyponatraemia. The patient concerned was a polytraumatized female patient, with a gradual onset of her symptoms, starting from the day 15 following the trauma. A pharmacological treatment failed. The loss of water and ions was supplemented mainly via i.v. route. 54 days later, the patient had no signs of the syndrome and the substitution could be withdrawn.

        Key words: CSWS – SIADH – hyponatraemia – osmolality – ADH