Hyperthyroidism and Thyroid Storm

Abstract

Thyrotoxicosis and thyroid storm are disease states that result from thyroid hormone-induced hypermetabolism. The excess thyroid hormone is released from the thyroid gland as a result of excess thyroid hormone production, or by processes that disrupt the follicular structure of the gland with subsequent release of stored hormone. True hyperthyroidism results from increased synthesis and release of thyroid hormone and can be distinguished from other causes of thyrotoxicosis by the thyroid 131I uptake. Graves' disease is the most common cause of hyperthyroidism and occurs most often in women aged 30 to 50 years. The classic features of a patient with fully developed Graves' disease are difficult to overlook, but the clinical features of thyrotoxicosis vary with the etiology of the disease and the sensitivity of the patient's peripheral tissues. Thyroid storm presents with an exaggeration of the features of uncomplicated thyrotoxicosis and, in addition, an alteration in mental status. Thyroid storm may lead to irreversible cardiovascular collapse and death if proper treatment is not initiated in the Emergency Department. Specific therapy of hyperthyroidism follows several strategies, including inhibition of hormone synthesis and release, inhibition of peripheral conversion of T4 to T3, and blocking of the systemic effects of excess thyroid hormone. Treatments directed at these ends may be initiated rapidly in the emergency setting.