Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.
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.
Many diseases and conditions can cause hyperthyroidism, including:
Common symptoms include:
Other symptoms that can occur with this disease:
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:
Imaging tests of the thyroid may also be needed, including:
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, tremor, sweating, and anxiety until the hyperthyroidism can be controlled.
Hyperthyroidism is treatable. Some 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.
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. People need to be treated in the hospital.
Other complications of hyperthyroidism include:
Surgery-related complications, including:
Call your 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 provider if you are being treated for hyperthyroidism and you develop symptoms of underactive thyroid, including:
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.