Switching of Hashimoto Thyroiditis Into Graves’ Disease: A Case Report and Literature Review

This case report described a rare instance of a 20-year-old female patient whose Hashimoto thyroiditis (HT) transitioned into Graves’ disease (GD). Initially, she presented with symptoms of hypothyroidism, including fatigue, weight gain, and hair loss, and was diagnosed with HT based on elevated TSH and anti-TPO antibodies. After starting levothyroxine treatment, her symptoms shifted to those of hyperthyroidism, with decreased TSH and increased T3, T4, and TSAb levels, leading to a GD diagnosis. The patient achieved full remission five weeks after treatment. The report highlighted that although the switch from HT to GD was uncommon, early diagnosis and treatment were crucial for improving patient care.