Oncological emergencies: syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Excessive secretion of vasopressin in the course of Syndrome of Inappropriate Antidiuretic Hormone Secretion is a common cause of hyponatremia in cancer patients. Clinical symptoms depend on the cause, rate of change of sodium level and their absolute values. Treatment options include fluid restrictions, intravenous administration of hypertonic sodium chloride solutions, loop diuretics and vaptans. The sodium level should not be adjusted too fast, because it may lead to irreversible brain damage. The article presents pathophysiology, diagnostics and recommendations of management of this oncological emergency.