Chronic polydipsia and polyuria as rare renal manifestations of Sjögren's syndrome.

Sjögren's syndrome is a chronic autoimmune disorder that primarily affects the exocrine glands, with renal involvement observed in a minority of cases. We present the case of a 31-year-old woman with an 8-year history of chronic polydipsia and polyuria who was ultimately diagnosed with Sjögren's syndrome. Comprehensive evaluation revealed distal renal tubular acidosis, incomplete nephrogenic diabetes insipidus, and autoimmune serology consistent with Sjögren's syndrome. Treatment with bicarbonate, electrolyte supplementation, and immunosuppressive therapy led to significant improvement in both clinical symptoms and renal function. This case highlights the importance of considering Sjögren's syndrome in patients with chronic, unexplained polydipsia and polyuria to ensure timely diagnosis and prevent prolonged symptom persistence.