There are really not many emergencies that we need to worry about regarding the thyroid gland - but thyroid storm is one of the rare exceptions. Thyroid storm is a medical emergency condition and needs to be treated immediately; even before all confirmatory diagnostic tests are performed.
What is Thyroid Storm?
Thyroid storm is a crisis or life-threatening condition characterized by an exaggeration of the usual physiologic response seen in hyperthyroidism. Whereas hyperthyroidism can cause symptoms such as sweating, feeling hot, palpitations and weight loss - symptoms of thyroid storm are more severe, resulting in complications such as:
- rapid heart rate
- irregular heart beat
- heart failure
Fever tends to be one of the hallmark signs of thyroid storm and can be as high as 105-106 F (40.5-41.1 C). The actual diagnosis of thyroid storm is made on the basis of suspicion in patients with symptoms described above and physical findings of an enlarged thyroid gland (thyromegaly), wide pulse pressure, and exophthalmos (protruding eyes). Not all affected individuals will exhibit all symptoms. These symptoms in addition to the findings of elevated thyroid hormones and other tests that may be performed emergently provide a strong presumptive diagnosis of thyroid storm. Conditions such as severe sepsis, pheochromocytoma, and malignant hyperthermia can mimic thyroid storm; consequently, determination of a definitive diagnosis should still be performed with appropriate tests.
Thyroid Storm Cause
Causes of thyroid storm may include:
- discontinuing needed medications for hyperthyroidism
- over-replacement of thyroid hormone
- recent treatment with radioactive iodine
- severe infection or illness, usually in a patient with hyperthyroidism
- severe medical stressors, such as heart attack, in a patient with hyperthyroidism
Thyroid storm requires emergent treatment and hospitalization. The main treatment is to decrease the circulating thyroid hormone levels and decrease their formation. Moreover, the high fever and possible dehydration is treated emergently with cooling of the body and IV hydration. PTU and methimazole are two agents that decrease thyroid hormone synthesis and are usually prescribed in fairly high doses. To inhibit thyroid hormone release from the thyroid gland, sodium iodide, potassium iodide and/or Lugol's solution can be given. Beta blockers such as propranolol (Inderal, Inderal LA) can help to control the heart rate, and intravenous steroids may be used to help support the circulation.
Earlier in this century, the mortality of thyroid storm approached 100%. However, now, with early clinical recognition and the use of aggressive therapy as described above, the death rate from thyroid storm is less than 20%.
Medically reviewed by John A. Seibel, MD; Board Certified Internal Medicine with a subspecialty in Endocrinology & Metabolism
Medscape. Hyperthyroidism, Thyroid Storm, and Graves Disease.