A 28-year-old woman presents with palpitations, high fever, agitation, tremor, and atrial fibrillation; what is the most likely diagnosis?

• A. Thyroid storm
• B. Delirium tremens
• C. Myxedema coma
• D. Sepsis

Answer: (A)

This presentation exemplifies a thyroid storm, a life-threatening surge of thyrotoxicosis. The extreme hypermetabolic state driven by excess thyroid hormone causes high fever, agitation, tremor, and marked sympathetic activation, which often leads to tachyarrhythmias such as atrial fibrillation. In a young woman, this pattern is especially suggestive if Graves disease or other thyrotoxic conditions are possible, and a precipitating factor like infection can trigger the crisis. Other conditions might produce fever or tremor or agitation, but the combination with atrial fibrillation and the overall hyperadrenergic picture fits thyroid storm much more than delirium tremens (which relies on withdrawal history), myxedema coma (hypothermia, bradycardia, hypotension), or sepsis (infections can cause fever and tachycardia but not the characteristic thyrotoxic features). Treatment involves rapid control of the thyroid axis and adrenergic symptoms to prevent hemodynamic collapse.