Hyponatraemia—treatment standard 2024.

This article focuses on the diagnosis and treatment of hyponatraemia, the most common electrolyte disorder in hospitalized patients, emphasizing its management based on severity, volume status, and underlying causes. Severe symptomatic hyponatraemia requires urgent correction with 3% hypertonic saline administered as rapid intermittent boluses or continuous infusion, with careful monitoring to avoid overcorrection and osmotic demyelination syndrome. For mild to moderate hyponatraemia, treatment varies by volume status: fluid replacement for hypovolaemic cases, fluid restriction for hypervolaemic and euvolaemic states, particularly in syndrome of inappropriate antidiuretic hormone secretion (SIADH), where nearly half of patients do not respond to fluid restriction alone. Second-line therapies for SIADH include oral urea and tolvaptan, though evidence guiding their choice remains limited; sodium–glucose co-transporter 2 (SGLT2) inhibitors show emerging potential. Close biochemical monitoring and individualized treatment adjustments are essential to optimize outcomes and minimize complications.