Résumé : Hyponatremia, defined as a serum sodium concentration <135 mmol/l, is the most common water-electrolyte imbalance encountered in clinical practice. It can lead to a wide spectrum of clinical symptoms, from mild to severe or even life threatening, and is associated with increased mortality, morbidity and length of hospital stay. Despite this, the management of hyponatremia patients remains problematic. The prevalence of hyponatremia in a wide variety of conditions and the fact that hyponatremia is managed by clinicians with a broad variety of backgrounds have fostered diverse institution- and specialty-based approaches to diagnosis and treatment. To obtain a common and holistic view, the European Society of Intensive Care Medicine (ESICM), the European Society of Endocrinology (ESE) and the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA), represented by European Renal Best Practice (ERBP), have developed clinical practice guidelines on the diagnostic approach and treatment of hyponatremia as a joint venture of 3 societies representing specialists with a natural interest in hyponatremia. In addition to a rigorous approach to the methodology and evaluation of the evidence, the document focuses on patient-positive outcomes and on providing a useful tool for clinicians involved in everyday practice. In this article, we present an abridged version of the recommendations and suggestions for the diagnosis and treatment of hyponatremia extracted from the full guide.