[An Endocrinological Perspective on Electrolyte Imbalances]

Electrolyte disorders are among the most frequent presentations in emergency internal medicine and may represent initial manifestations of underlying endocrine disease. This review highlights the pathophysiological background, diagnostic strategies and therapeutic recommendations for electrolyte imbalances in endocrine emergencies.

Hyponatremia still marks the most prevalent electrolyte disorder and may indicate underlying adrenal insufficiency, hypopituitarism, the syndrome of inappropriate antidiuresis (SIAD), or immunotherapy-induced endocrinopathies. The diagnostic evaluation includes clinical volume assessment and paired measurements of serum and urine sodium and osmolality. Acute symptomatic hyponatremia requires immediate correction using hypertonic saline, overcorrection can be avoided by using proactive or reactive desmopressin protocols. SIAD remains a diagnosis of exclusion, with fluid restriction remaining first-line therapy and osmotic agents and tolvaptan as second-line options. Hypernatremia may occur in the context of diabetes insipidus and requires careful fluid management and, in central forms, desmopressin substitution. Hypokalemia can result from hyperaldosteronism or hypercortisolism and should prompt endocrine evaluation, especially in patients with hypertension. Hypercalcemia is frequently caused by hyperparathyroidism but may also be present in thyrotoxicosis, adrenal insufficiency or due to excessive intake of cholecalciferol or lithium.

Electrolyte disturbances may serve as important clinical indicators and red flags of endocrine disorders. Early recognition and targeted diagnostic and therapeutic strategies are essential to prevent life-threatening complications. This review provides a structured approach for clinicians to evaluate and manage electrolyte disorders with a focus on endocrine etiologies in acute care settings.