Abstract
Myxoedema coma is a rare but life-threatening manifestation of hypothyroidism with high associated mortality. We present the case of a man in his sixties with known hypothyroidism and alcohol dependence who collapsed at home with profound hypothermia, refractory hypoglycaemia, hypoxia and reduced consciousness. Initial findings were easily attributable to excess alcohol; however, clinical features including periorbital oedema and bedside echocardiogram revealed moderate pericardial effusion, which prompted further investigation. Thyroid function tests confirmed severe hypothyroidism with elevated thyroid-stimulating hormone and suppressed free T3 and free T4 levels. Imaging revealed a substantial pericardial effusion and left basal pneumonia. The patient was treated with intravenous glucose, active warming, hydrocortisone and intravenous thyroxine along with antibiotics and supportive care. The patient achieved steady clinical and biochemical improvements following critical care admission. This case highlights the diagnostic challenge of recognising myxoedema coma and emphasises the importance of maintaining a high index of suspicion for endocrine emergencies.