Hyponatraemia is the most common electrolyte abnormality, encountered in up to 30% of inpatients. Inappropriate management can have serious implications for patients; including demyelinating disease, coma and death. We have used a case report to identify the common problems, and provide useful strategies in management for which these can be avoided. The aim was to provide a framework which clinicians can adopt, in order to improve clinical practice and provide optimum outcome for the patient.