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Hyperthyroidism Overview

Hyperthyroidism refers to any condition in which there is too much thyroid hormone in the body. It is sometimes referred to as overactive thyroid. Excess thyroid hormone levels can increase metabolism (how energy is used), and increase the risk of other health issues such as heart disease, bone loss, and problems during pregnancy.

Hyperthyroidism Causes

Common causes of hyperthyroidism in adults include:

  • Diffuse Toxic Goiter (Graves' Disease)
    • Overactivity of the entire thyroid gland caused by antibodies in the blood which stimulate the thyroid to grow and secrete excessive amounts of thyroid hormone
  • Toxic Adenoma ("hot nodule")
    • A dominant thyroid nodule, or lump, is overactive and secretes excess thyroid hormone
  • Toxic Multinodular Goiter (Plummer's disease)
    • One or more nodules or lumps in the thyroid becomes overactive
  • Subacute Thyroiditis
    • Hyperthyroid phase of subacute thyroiditis, caused by viral infection or postpartum inflammatory process
    • Due to thyroid inflammation, excess hormone is released into the blood circulation
    • More than 90% of affected individuals will go back to normal thyroid function without treatment.
  • Drug-Induced Hyperthyroidism
    • Iodine-induced hyperthyroidism: older population, typically in setting of preexisting nontoxic nodular goiter
    • amiodarone (Cordarone)
    • Iodine-containing contrast material used in radiology studies
Medically Reviewed by a Doctor on 11/10/2014
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Read What Your Physician is Reading on Medscape

Hyperthyroidism »

Thyrotoxicosis is the hypermetabolic condition associated with elevated levels of free thyroxine (FT4), free triiodothyronine (FT3), or both.

Read More on Medscape Reference »

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