Unraveling the Mystery of Recurrent Fatigue and Hypokalemia: A Case of Sjögren’s Syndrome Complicated by Renal Tubular Acidosis

A 55-year-old female presented with progressive fatigue over two months, accompanied by intermittent muscle twitching and hypokalemia. Initial evaluations revealed that potassium levels fluctuated between 3.01 mmol/L and 3.43 mmol/L, leading to potassium supplementation treatment. Although her symptoms improved temporarily, they persisted, requiring further investigations. Comprehensive assessments, including blood tests, CT scans, and specialized hormone tests, were conducted and initially suggested primary hyperaldosteronism; however, this was ruled out after an aldosterone suppression test.Ultimately, Sjögren's syndrome with renal tubular acidosis was diagnosed based on specific autoantibody positivity and symptom correlation. The patient was subsequently referred to the rheumatology department for targeted management. This case underscores the complexities involved in diagnosing multifactorial fatigue and recurrent hypokalemia, and it emphasizes the critical importance of thorough clinical evaluation and interdisciplinary collaboration in identifying underlying autoimmune disorders.