What are the causes of hyperthyroidism?

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Last updated: March 7, 2025 • View editorial policy

From the Guidelines

Hyperthyroidism is primarily caused by Graves' disease, Hashimoto thyroiditis, and functional thyroid nodules, as well as other factors such as female sex, advancing age, and low iodine intake. The causes of hyperthyroidism can be broken down into several key categories, including:

  • Autoimmune disorders, such as Graves' disease, where antibodies stimulate the thyroid to produce excess hormones 1
  • Thyroiditis, or inflammation of the thyroid, which can cause temporary hormone release
  • Excessive iodine intake, which can stimulate the thyroid to produce more hormones
  • Taking too much thyroid medication, which can lead to an overactive thyroid
  • Other less common causes, such as pituitary tumors producing excess TSH, hCG elevation during pregnancy, and certain medications like amiodarone or lithium 1 The risk factors for developing hyperthyroidism include female sex, advancing age, black race, low iodine intake, and a personal or family history of thyroid disease 1. Treatment for hyperthyroidism depends on the underlying cause and may include anti-thyroid medications, radioactive iodine therapy, or surgery, with the goal of reducing morbidity, mortality, and improving quality of life.

From the Research

Causes of Hyperthyroidism

  • The most common cause of hyperthyroidism is Graves' disease, which is characterized by the presence of autoantibodies directed against the thyrotropin receptor (TRAb) that cause overproduction and release of thyroid hormones 2, 3, 4, 5, 6.
  • Other common causes of hyperthyroidism include: + Thyroiditis, which can cause an excessive passive release of thyroid hormones 3, 4, 6. + Toxic multinodular goiter, which can cause an excessive production of thyroid hormones 3, 4, 6. + Toxic adenomas, which can cause an excessive production of thyroid hormones 3, 4, 6. + Side effects of certain medications 3.
  • Hyperthyroidism can also be caused by an endogenous or exogenous extrathyroidal source, such as an excessive release of preformed thyroid hormones 4.

Characteristics of Hyperthyroidism Causes

  • Graves' disease is the most frequent cause of hyperthyroidism in iodine-sufficient geographical areas 2, 5.
  • Thyroiditis can cause a transient hyperthyroidism, which usually requires only symptomatic treatment 3, 4, 6.
  • Toxic multinodular goiter and toxic adenoma can be treated with radioactive iodine, antithyroid drugs, or surgery 3, 4, 6.
  • The presence of Graves' orbitopathy can change the management of Graves' disease, and may require additional treatments such as intravenous glucocorticoids or target-based therapies 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.