When the Expected Becomes Unexpected: An Acute Presentation of Hypothyroidism.

Myxedema coma is an uncommon and life-threatening manifestation of severe hypothyroidism. Its occurrence in the pediatric population is exceptionally rare and can result from long-standing untreated hypothyroidism or nonadherence to treatment. Identifying this condition can be challenging because it requires a high level of clinical suspicion along with thyroid function testing. We present a 17-year-old female with a history of anxiety who had widespread nonspecific symptoms, including persistent bradycardia, which were found to be caused by hypothyroidism. Our goal is to raise awareness of the varied clinical manifestations of pediatric myxedema to promote early recognition and prompt medical interventions that can lead to better outcomes.