Background: Hyponatremia is a common endocrine disorder associated with prolonged hospital stays and increased morbidity. Accurate diagnosis and management require systematic clinical and biochemical assessments. This study evaluates the current practices in managing inpatient hyponatremia and compares them with international guidelines. Objectives: This study aims to (1) compare current hyponatremia management practices with international guidelines, (2) identify areas needing improvement in documentation and service provision, and (3) implement changes and reassess outcomes. Methods: A retrospective randomized case note review of 50 inpatients diagnosed with hyponatremia was conducted. Documentation standards were compared with international guidelines. A second audit was performed after implementing a checklist-based documentation system. Results: The first audit revealed suboptimal documentation and testing: volume status was recorded in only 8% of cases, paired osmolality in 8%, medication review in 24%, urinary sodium in 28%, urinary osmolality in 36%, serum cortisol in 56%, and thyroid function tests in 72%. After implementing a standardized documentation sticker, documentation rates improved, with notable reductions in hospital stay duration and time to achieve sodium normalization across all severity groups. Mean hospital stay for severe hyponatremia decreased from 11.4 to 7.5 days. Conclusions: Implementing a standardized documentation checklist improved hyponatremia management, reduced hospital stay duration, and facilitated early specialist input. Further improvements could be achieved by updating hospital guidelines to align with international standards and introducing electronic alerts and referrals.