by EBSCO Medical Review Board
(Graves Disease; Overactive Thyroid)


Hyperthyroidism is an overactive thyroid. The thyroid gland is a butterfly-shaped gland in the front of the neck. It makes hormones that affect many areas of the body. An overactive thyroid makes too much hormone.

The Thyroid Gland
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Hyperthyroidism may be caused by:

  • Graves disease—the immune system attacks cells of the thyroid gland
  • One or more thyroid nodules
  • Thyroiditis—inflammation of the thyroid
  • Taking too much thyroid hormone

Risk Factors

Things that may increase your chance of hyperthyroidism include:

  • Pregnancy—postpartum thyroiditis (hyperthyroidism followed by hypothyroidism)
  • Family history of Graves disease
  • Certain viral infections
  • Smoking


Symptoms may show once the thyroid becomes more active. They often come on slowly. Examples include:

  • Easily overheated and increased sweating
  • Mood swings, nervousness, restlessness, or irritability
  • Fatigue
  • Heart palpitations or rapid or irregular pulse
  • Shortness of breath
  • Unexplained weight loss despite an increased appetite
  • Problems sleeping
  • Increase in bowel movements/diarrhea
  • Changes or lack of menstrual periods
  • Shaky hands
  • Dry, red eyes
  • Double vision


The doctor will ask about symptoms and past health. A physical exam will be done. Thyroid problems may be suspected. A blood tests will show levels of thyroid hormone. It can also show antibodies if the problems are caused by immune issues. A radioactive iodine uptake test may be done. It can show how well the thyroid is working.


Treatment will depend on what is causing the hyperthyroidism. Options include:

Antithyroid Medicine

Medicine can calm thyroid activity. It may bring hormone levels down to normal. Medicine may need to be adjusted over time.

Smoking can cause problems with some of the medicine. There are a different tools to help quit smoking.

Reduce or Remove Thyroid

The thyroid normally absorbs iodine. A form of iodine with radioactive material is taken by mouth. The thyroid absorbs the special iodine. The radioactive material damages most of the thyroid cells. This will decrease the amount of hormones made by the thyroid. Hormone replacement medicine may be needed if levels fall too much.

Thyroidectomy is the removal of all or part of the thyroid. It is an uncommon treatment of hyperthyroidism. It may be done if medical therapy fails.

Manage Symptoms

A type of medicine called beta-blockers may help symptoms. It may help to relieve rapid heart rate and nervousness.


There are no current steps to prevent hyperthyroidism.


American Thyroid Association 

Graves' Disease & Thyroid Foundation 


Health Canada 

Thyroid Foundation of Canada 


Hyperthyroidism. American Thyroid Association website. Available at: Accessed March 13, 2021.

Hyperthyroidism and Other Causes of Thyrotoxicosis. EBSCO DynaMed website. Available at: Accessed March 13, 2021.

Hyperthyroidism (Overactive Thyroid). The National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: Accessed March 13, 2021.

Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis. Thyroid. 2016 Oct;26(10):1343-1421.

Van Geest RJ, Sa sim IV, Koppeschaar HP, et al. Methylprednisolone pulse therapy for patients with moderately severe Graves orbitopathy: a prospective, randomized, placebo-controlled study. Eur J Endocrinol. 2008;158(3):229-237.

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