The Unlikely Suspect: A Case Report of New-Onset Hyperthyroidism Due to Graves' Disease in an 89-Year-Old Gentleman and Review of Literature.

Thyroid dysfunction in the elderly commonly manifests as hypothyroidism. With advancing age, toxic nodules are the more common cause of hyperthyroidism as compared to Graves' disease. Due to the lack of classical symptoms of hyperthyroidism in the elderly, the diagnosis can often be delayed. Previously, an 82-year-old gentleman with oropharyngeal dysphagia due to Graves' disease was the oldest reported case with atypical symptoms. We report a case of an 89-year-old gentleman with no prior history of thyroid disease, who presented with non-specific gastrointestinal symptoms that ultimately led to the diagnosis of hyperthyroidism secondary to Graves' disease. We also review the available literature regarding the pathophysiology, clinical presentation, and management of hyperthyroidism and Graves' disease in the elderly.