Hyponatremia Is Associated With Urinary Retention: The Vasopressin-Dependent and -Independent Pathways

Hyponatremia has numerous causes, and the vasopressin-independent and vasopressin-responsive pathways have been associated with the condition. Herein, we aimed to present a case of hyponatremia induced by urinary retention, a rare cause of hyponatremia. A woman in her 80s presented to the emergency department with malaise and difficulty in movement. Plasma sodium levels of 118 mEq/L, urinary retention, and an Escherichia coli urinary tract infection were detected. Her condition and plasma sodium levels resolved through urinary catheterization, sodium administration, and antibiotic treatment. Evaluating serum vasopressin levels aids in differentiating between urinary retention and hyponatremia, and urinary retention treatment is crucial regardless of the etiology.