Thyroid storm is a term used to describe a rare disorder that may develop in patients with unrecognized or untreated Graves’ disease. It may represent an extreme reaction that occurs as a result of exposure to excess amounts of thyroid hormone. Patients who develop thyroid storm are usually noted to have many of the same findings associated with less severe forms of thyrotoxicosis. For reasons that are unclear, their symptoms and physical signs become amplified to the point where they may become life-threatening. Most patients who develop thyroid storm present with high fevers, accelerated heart rates, nausea, vomiting, diarrhea, irritability, anxiety, and confusion. In severe cases, patients may present with abnormal heart rhythms, congestive heart failure, seizures, or coma.
Certain events that may be associated with the onset of thyroid storm. Episodes may be triggered by an underlying infection, an acute illness, childbirth, trauma, or surgery requiring general anesthesia. In the past, patients diagnosed with Graves’ disease who underwent subtotal thyroidectomies were at a higher risk for the development of thyroid storm, possible as a result of manipulation of the thyroid gland during surgery. Postsurgical thyroid storm has become much less common in the United States with the emergence of radioactive iodine therapy as a preferred form of treatment. On rare occasions, patients with severe Graves’ disease who undergo treatment with radioactive iodine therapy may develop thyroid storm as a complication.