# Sodium and Water Homeostasis in Children: Pathogenesis, Diagnosis, and Treatment

## TL;DR

This paper reviews how children manage sodium and water balance, focusing on diagnosing and treating related disorders to improve patient care.

## Contribution

The paper provides updated diagnostic and treatment guidelines for pediatric sodium-water disorders based on recent scientific and clinical insights.

## Key findings

- Sodium disorders in children should be evaluated in the context of vascular volume status.
- The review emphasizes conditions like cerebral salt wasting and diabetes insipidus in pediatric clinics.
- Updated management strategies are proposed to reduce complications in children with sodium imbalances.

## Abstract

Maintaining homeostasis in the body through water and sodium management is essential, and the central nervous system and kidneys play a key role in this process. However, knowledge of the diagnosis and treatment of these conditions in pediatric patients is still unsystematized. There are no up-to-date guidelines on managing children with sodium imbalance. Since sodium shifts are inextricably linked to water changes in the body, they should always be pondered together. Each of the sodium disorders should be considered in the context of changes in the vascular volume, whether it is hypo-, eu-, or hypervolemic. This review describes the most common sodium-water disorders encountered in pediatric clinics. It emphasizes conditions affecting the brain-kidney axis (syndrome of inappropriate antidiuresis, cerebral salt wasting syndrome, and central and nephrogenic diabetes insipidus). The article proposes diagnostic and therapeutic management based on scientific society publications, case series, and the authors’ clinical experience, and summarizes the available knowledge as of 2025 to improve the care of patients with hyponatremia or hypernatremia. A proper understanding of the physiology of sodium homeostasis is crucial for implementing appropriate treatment and reducing the risk of severe complications in young patients in the future.