Myxedema Coma Complicated by Pericardial Effusion and Early Cardiac Tamponade.

We report the case of a 70-year-old female with a history of hypothyroidism who presented following an unwitnessed fall with bradycardia and hypothermia. She was found to have myxedema coma complicated by signs of early cardiac tamponade, requiring urgent pericardiocentesis. Myxedema coma is a rare but life-threatening manifestation of severe decompensated hypothyroidism, carrying a high mortality rate despite treatment. It commonly presents with hypothermia and altered mental status and may be precipitated by infection, trauma, medication nonadherence, or cold exposure. Early recognition and prompt treatment with intravenous stress-dose steroids and thyroid hormone replacement are essential to improve outcomes. This case highlights the potentially severe complications of inadequately treated hypothyroidism. It emphasizes the importance of considering cardiac tamponade as a rare but life-threatening consequence of this disease, requiring a high index of suspicion, timely diagnosis, and urgent intervention.