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Hyperthyroidism, Thyroid Storm, and Graves Disease

Authors: Erik D. Schraga, MDAuthor Information and Disclosures

Editors: Robin R. Hemphill, MD, MPH; Francisco Talavera, PharmD, PhD; Howard A. Bessen, MD; John Halamka, MD; Rick Kulkarni, MDEditor Information

Last Updated: May 24, 2006

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Introduction

Background: Hyperthyroidism, thyroid storm, and Graves disease are conditions of excess thyroid hormone. The elevated level of thyroid hormones can result in clinical manifestations ranging from mild to severely toxic with resultant morbidity and mortality for affected patients.

Hyperthyroidism

Hyperthyroidism presents as a constellation of symptoms due to elevated levels of circulating thyroid hormones. Because of the many actions of thyroid hormone on various organ systems in the body, the spectrum of clinical signs produced by the condition is broad. The presenting symptoms can be subtle and nonspecific, making hyperthyroidism difficult to diagnose in its early stages without the aid of laboratory data.

The term hyperthyroidism refers to inappropriately elevated thyroid function. Though often used interchangeably, the term thyrotoxicosis, which is an excessive amount of circulating thyroid hormone, is not synonymous with hyperthyroidism. Increased levels of hormone can occur despite normal thyroid function, such as in instances of inappropriate exogenous thyroid hormone or excessive release of stored hormone from an inflamed thyroid gland.

Graves disease

Graves disease (diffuse toxic goiter), the most common form of overt hyperthyroidism, is an autoimmune condition in which autoantibodies are directed against the thyroid-stimulating hormone (TSH) receptor. As a result, the thyroid gland is inappropriately stimulated with ensuing gland enlargement and increase of thyroid hormone production. Risk factors for Graves disease include family history of hyperthyroidism or various other autoimmune disorders, high iodine intake, stress, use of sex steroids, and smoking. The disease is classically characterized by the triad of goiter, exophthalmos, and pretibial myxedema.

Thyroid storm

Thyroid storm is a rare and potentially fatal complication of hyperthyroidism. It typically occurs in patients with untreated or partially treated thyrotoxicosis who experience a precipitating event such as surgery, infection, or trauma. Thyroid storm must be recognized and treated on clinical grounds alone, as laboratory confirmation often cannot be obtained in a timely manner. Patients typically appear markedly hypermetabolic with high fevers, tachycardia, nausea and vomiting, tremulousness, agitation, and psychosis. Late in the progression of disease patients may become stuporous or comatose with hypotension.

Pathophysiology: In healthy patients, the hypothalamus produces thyrotropin-releasing hormone (TRH), which stimulates the anterior pituitary gland to secrete thyroid-stimulating hormone (TSH); this in turn triggers the thyroid gland to release thyroid hormone.

Thyroid hormone concentration is regulated by negative feedback by circulating free hormone primarily on the anterior pituitary gland and to a lesser extent on the hypothalamus. The secretion of TRH is also partially regulated by higher cortical centers.

The thyroid gland produces the prohormone thyroxine (T4), which is deiodinated primarily by the liver and kidneys to its active form, triiodothyronine (T3). The thyroid gland also produces a small amount of T3 directly. T4 and T3 exist in 2 forms: a free, unbound portion that is biologically active and a portion that is protein bound to thyroid-binding globulin (TBG). Despite consisting of less than 0.5% of total circulating hormone, free or unbound T4 and T3 levels best correlate with the patient's clinical status.

Frequency:

  • In the US: The overall incidence of hyperthyroidism is estimated between 0.05 to 1.3%, with the majority consisting of subclinical disease. The prevalence of hyperthyroidism is approximately 5-10 times less than hypothyroidism.

    Thyroid storm is a rare disorder. Approximately 1-2% of patients with hyperthyroidism progress to thyroid storm.

Mortality/Morbidity:

  • Thyroid storm, if unrecognized and untreated, is often fatal.
  • Adult mortality rate from thyroid storm is approximately 10-20%, but it has been reported to be as high as 75% in hospitalized populations. Underlying precipitating illness may contribute to high mortality.

Race:

  • White and Hispanic populations in the United States have a slightly higher prevalence of hyperthyroidism in comparison with black populations.

Sex:

  • A slight predominance of hyperthyroidism exists among females.

Age:

  • Thyroid storm may occur at any age but is most common in those in their third through sixth decades of life.
  • Graves disease predominantly affects those aged 20-40 years.
  • The prevalence of toxic multinodular goiter increases with age and becomes the primary cause of hyperthyroidism in elderly persons.

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Bibliography

  1. Basaria S, Cooper DS: Amiodarone and the thyroid. Am J Med 2005 Jul; 118(7): 706-14[Medline].
  2. Braverman LE, Utiger RD: Werner and Ingbar's the Thyroid: A Fundamental and Clinical Text. 7th ed. 1996.
  3. Burch HB, Wartofsky L: Life-threatening thyrotoxicosis. Thyroid storm. Endocrinol Metab Clin North Am 1993 Jun; 22(2): 263-77[Medline].
  4. Canaris GJ, Manowitz NR, Mayor G, Ridgway EC: The Colorado thyroid disease prevalence study. Arch Intern Med 2000 Feb 28; 160(4): 526-34[Medline].
  5. Cappola AR, Fried LP, Arnold AM, et al: Thyroid status, cardiovascular risk, and mortality in older adults. JAMA 2006 Mar 1; 295(9): 1033-41[Medline].
  6. Carlson HE: Gynecomastia. N Engl J Med 1980 Oct 2; 303(14): 795-9[Medline].
  7. Fisher JN: Management of thyrotoxicosis. South Med J 2002 May; 95(5): 493-505[Medline].
  8. Gharib H: Changing concepts in the diagnosis and management of thyroid nodules. Endocrinol Metab Clin North Am 1997 Dec; 26(4): 777-800[Medline].
  9. Glauser J, Strange GR: Hypothyroidism and hyperthyroidism in the elderly. Emerg Med Rep 2002; 1(2): 1-12.
  10. Hollowell JG, Staehling NW, Flanders WD, et al: Serum TSH, T(4), and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab 2002 Feb; 87(2): 489-99[Medline].
  11. Kudrjavcev T: Neurologic complications of thyroid dysfunction. Adv Neurol 1978; 19: 619-36[Medline].
  12. McKeown NJ, Tews MC, Gossain VV, Shah SM: Hyperthyroidism. Emerg Med Clin North Am 2005 Aug; 23(3): 669-85, viii[Medline].
  13. Pimentel L, Hansen KN: Thyroid disease in the emergency department: a clinical and laboratory review. J Emerg Med 2005 Feb; 28(2): 201-9[Medline].
  14. Ragland E, Urbanic RC: Thyroid emergencies. In: Harwood-Nuss Al, Linden CH, eds. The Clinical Practice of Emergency Medicine. 2nd ed. Lippincott Williams & Wilkins; 1996:736-41.
  15. Ragland, G: Thyroid storm. In: Emergency Medicine: A Comprehensive Study Guide. 4th ed. New York, NY: McGraw Hill; 1996:736-9.
  16. Ringel MD: Management of hypothyroidism and hyperthyroidism in the intensive care unit. Crit Care Clin 2001 Jan; 17(1): 59-74[Medline].
  17. Rozien MF: Anesthetic implications of concurrent diseases. In: Anesthesia. 4th ed. New York, NY: Churchill Livingstone; 1994:926-8.
  18. Rozien MF, Fleisher LA: Essence of Anesthesia Practice. WB Saunders Co; 1997:177.
  19. Scott SK: Thyroid disorders. In: Markovchick VJ, Pons PT, Wolfe RE, eds. Emergency Medicine Secrets. Hanley and Belfus; 1993:178-82.
  20. Sniezek JC, Francis TB: Inflammatory thyroid disorders. Otolaryngol Clin North Am 2003 Feb; 36(1): 55-71[Medline].
  21. Streetman DD, Khanderia U: Diagnosis and treatment of Graves disease. Ann Pharmacother 2003 Jul-Aug; 37(7-8): 1100-9[Medline].
  22. Tietgens ST, Leinung MC: Thyroid storm. Med Clin North Am 1995 Jan; 79(1): 169-84[Medline].
  23. Waldstein SS, Slodki SJ, Kaganiec GL: A clinical study of thyroid storm. Ann Intern Med 1960; 52: 626-42.
  24. Warofsky L, Ingbar SH: Diseases of the thyroid. In: Wilson JD, Brunwald E, et al, eds. Harrison's Principles of Internal Medicine. McGraw-Hill; 1991:1692-1712.
  25. Weetman AP: Graves' disease. N Engl J Med 2000 Oct 26; 343(17): 1236-48[Medline].
  26. Wogan JM: Endocrine disorders. In: Rosen P, Barkin RM, et al, eds. Emergency Medicine: Concepts and Clinical Practice. Mosby-Year Book; 1992:2242-59.

Hyperthyroidism, Thyroid Storm, and Graves Disease excerpt

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Author Information and Disclosures

Author: Erik D. Schraga, MD, Consulting Staff, Permanente Medical Group, Kaiser Permanente, Santa Clara Medical Center

Coauthor(s): Craig A. Manifold, DO, Associate Program Director, Department of Emergency Medicine, Wilford Hall Medical Center

Erik D Schraga, MD, is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Emergency Medicine Residents' Association

Editor Information

Robin R Hemphill, MD, MPH, Associate Professor, Director, Disaster Preparedness, Department of Emergency Medicine, Vanderbilt University Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Howard A Bessen, MD, Professor of Medicine, UCLA School of Medicine; Program Director, Department of Emergency Medicine, Harbor-UCLA Medical Center; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Rick Kulkarni, MD, Medical Director, Assistant Professor of Surgery, Section of Emergency Medicine, Yale-New Haven Hospital

 
 
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