A Case Series of Hyponatremia

Hyponatremia is one of the challenging electrolyte abnormalities encountered in clinical medicine, posing significant diagnostic and therapeutic challenges. Even minor deviations from the physiological sodium baseline are associated with considerable morbidity and an exponentially increased risk of mortality. While the fundamental tenets of volume regulation and osmolality are well-established, the clinical presentation of hyponatremia is frequently confounded by overlapping systemic illnesses, neuroanatomical vulnerabilities, and iatrogenic interventions. This case series meticulously details the clinical trajectories of four unique patients presenting with hyponatremia in the context of highly complex, multifactorial etiologies. The first case examines hyponatremia and complicating acute bilateral pyelonephritis and uncontrolled diabetes mellitus. The second case elucidates a catastrophic instance of Osmotic Demyelination Syndrome (ODS) that was insidiously unmasked following an episode of hypertensive encephalopathy and the subsequent diagnosis of the Syndrome of Inappropriate Antidiuretic Hormone (SIADH). The third case details a highly volatile presentation of fluctuating hyponatremia, SIADH and multi-lobar consolidation in a patient with severe chronic alcohol use disorder and the last case demonstrates hyponatremia secondary to a CNS infection. Through an exhaustive analysis of these clinical scenarios, this report highlights the critical necessity of proper diagnosis and individualised mathematically constrained sodium correction protocols. It demonstrates that uncommon and devastating sodium-related complications, such as pontine myelinolysis and SIADH, frequently arise when acute infectious processes or mechanical vascular trauma overwhelm the cellular osmotic buffering capacity of the central nervous system.