• synonyms


[hahy-per-thahy-roi-diz-uh m]
noun Pathology.
  1. overactivity of the thyroid gland.
  2. a condition resulting from this, characterized by increased metabolism and exophthalmos.
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Origin of hyperthyroidism

First recorded in 1895–1900; hyper- + thyroid + -ism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for hyperthyroidism

Historical Examples

  • Hyperthyroidism is eight times more common in women than in men.

    When You Don't Know Where to Turn

    Steven J. Bartlett

  • The classical symptoms of hyperthyroidism are staring eyes and enlargement of the neck, but these need not be present.

British Dictionary definitions for hyperthyroidism


  1. overproduction of thyroid hormone by the thyroid gland, causing nervousness, insomnia, sweating, palpitation, and sensitivity to heatAlso called: thyrotoxicosis See exophthalmic goitre
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Derived Formshyperthyroid, adjective, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for hyperthyroidism


1895, from hyper- + thyroid + -ism.

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Online Etymology Dictionary, © 2010 Douglas Harper

hyperthyroidism in Medicine


  1. Pathologically excessive production of thyroid hormones.
  2. The condition resulting from excessive activity of the thyroid gland, characterized by increased basal metabolism.
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Related formshy′per•thyroid adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

hyperthyroidism in Science


  1. An abnormality of the thyroid gland characterized by excessive production of thyroid hormone, which can result in an increased basal metabolic rate, causing weight loss, heart palpitations, and tremors. Compare hypothyroidism.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.