PT - JOURNAL ARTICLE AU - Punith Kempegowda AU - Ananth U Nayak TI - Thyrotoxicosis in patients with hypothyroidism is not just overtreatment AID - 10.1136/bcr-2017-221061 DP - 2017 Jul 14 TA - BMJ Case Reports PG - bcr-2017-221061 VI - 2017 4099 - http://casereports.bmj.com/content/2017/bcr-2017-221061.short 4100 - http://casereports.bmj.com/content/2017/bcr-2017-221061.full AB - A 62-year-old Caucasian woman presented with hypothyroid symptoms and biochemical thyrotoxic picture. Previously, she underwent right-sided subtotal thyroidectomy and left partial thyroid lobectomy for thyroid lumps, and treated with thyroxine replacement for hypothyroidism. Although there were no significant findings on clinical examination, investigations confirmed thyrotoxicosis with positive autoimmunity against thyroid gland—all in line with a diagnosis of Graves’ hyperthyroidism. We would like to highlight atypical presentations of thyroid dysfunction and conversion of underactive to overactive thyroid status with this case. Early recognition, diagnosis and intervention are essential to prevent and/or reduce associated morbidity and mortality. When encountered with such clinical conundrums, we recommend seeking opinion from an experienced endocrinologist while interpreting such situation.