Worsening Hypothyroidism in the Setting of New-Onset Nephrotic Syndrome.

We present a case of a 54-year-old female with well-controlled hypothyroidism who experienced worsening symptoms due to nephrotic syndrome. The patient presented with fatigue, progressive shortness of breath on exertion, and anasarca for one month. Laboratory results revealed significantly elevated thyroid-stimulating hormone levels and nephrotic range proteinuria. A kidney biopsy showed stage I membranous nephropathy with positive phospholipase A2 receptor (PLA2R) findings. Her symptoms gradually improved after receiving a higher dose of levothyroxine, along with diuretics and lisinopril initiation. She continued to be closely monitored by both endocrinology and nephrology outpatient services. This case report highlights the importance of closely monitoring hypothyroidism treatment when significant proteinuria is present.