Atrial fibrillation from thyroid storm.

Background: Thyroid storm is an often-discussed but rare presentation to emergency departments (EDs). The clinical presentation of a thyroid storm is the result of a hyperthyroid state that may result in significant morbidity or disability, or even death. Typically, patients are aware of their hyperthyroid condition, and may be able to recognize an episode of thyroid storm. However, the first presentation of hyperthyroidism could, in fact, be from thyrotoxic crisis.

Objectives: To review the presentation of thyroid storm, including tachycardia, hyperpyrexia, agitation, and altered mental status, which can be easily misdiagnosed as drug intoxication.

Case Report: We present the case of an otherwise healthy young adult who was sent to the ED by an outpatient care provider for generalized and vague symptoms of "feeling unwell" that was eventually diagnosed in the ED as thyrotoxic crisis.

Conclusion: We use this case to emphasize that thyrotoxic crisis should be at least considered in the differential diagnosis of a patient with this presentation, and to highlight how, even with apparently usual and effective treatments, a patient may still decompensate.