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The thyroid gland is a vitally important hormonal gland, which mainly works for body’s metabolism. It is located in the front part of the neck below the voice box and is butterfly-shaped. The functions of the thyroid gland include the production of the thyroid hormones triiodothyronine (T3) and tetraiodothyronine, also called thyroxine (T4).

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A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M.; 2013.

A.D.A.M. Medical Encyclopedia.

Hyperthyroidism

Thyrotoxicosis

Last reviewed: May 10, 2014.

Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.

Brain-thyroid link

Causes

The thyroid gland is an important organ of the endocrine system. It is located at the front of the neck just above where your collarbones meet. The gland makes the hormones that control the way every cell in the body uses energy. This process is called metabolism.

Thyroid gland

Many diseases and conditions can cause hyperthyroidism, including:

Symptoms

Common symptoms include:

Goiter

Other symptoms that can occur with this disease:

Endocrineglands

Exams and Tests

The health care provider will do a physical exam. The exam may find the following:

Blood tests are also ordered to measure your thyroid hormones TSH, T3, and T4.

You may also have blood tests to check: 

Treatment

Treatment depends on the cause and severity of symptoms. Hyperthyroidism is usually treated with one or more of the following:

If your thyroid is removed with surgery or destroyed with radioactive iodine, you must take thyroid hormone replacement pills for the rest of your life.

Medicines called beta-blockers may be prescribed to treat symptoms such as fast heart rate, sweating, and anxiety until the hyperthyroidism can be controlled.

Outlook (Prognosis)

Hyperthyroidism is treatable. Some of its causes may go away without treatment.

Hyperthyroidism caused by Graves disease usually gets worse over time. It has many complications, some of which are severe and affect quality of life.

Possible Complications

Thyroid crisis (storm) is a sudden worsening of hyperthyroidism symptoms that may occur with infection or stress. Fever, decreased alertness, and abdominal pain may occur. Patients need to be treated in the hospital.

Other complications of hyperthyroidism include:

  • Heart problems such as fast heart rate, abnormal heart rhythm, and heart failure
  • Osteoporosis

Surgery-related complications, including:

When to Contact a Medical Professional

Call your health care provider if you have symptoms of hyperthyroidism. Go to an emergency room or call the local emergency number (such as 911) if you have:

Call your health care provider if you are being treated for hyperthyroidism and you develop symptoms of underactive thyroid, including:

  • Depression
  • Mental and physical sluggishness
  • Weight gain

References

  1. Bahn RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other causes of thyrotoxicosis: Management Guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Endocr Pract. 2011;17:457-520. [PubMed: 21700562]
  2. Mandel SJ, Larsen PR, Davies TF. Thyrotoxicosis. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 12.

Review Date: 5/10/2014.

Reviewed by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

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  • Endocrine glands.
    Goiter.
    Brain-thyroid link.
    Thyroid gland.

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