Hyperthyroidism is too much thyroid hormone in the blood. The thyroid gland is in the front of the neck. It makes two hormones that control metabolism, such as:
Graves disease is the most common. It causes the immune system to make antibodies that cause the thyroid gland to make too much hormone.
Hyperthyroidism can also be from:
Treating hyperthyroidism can lead to hypothyroidism. This is when the gland does not make enough hormone.
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 May-Jun;17(3):456-520, also published in Thyroid 2011 Jun;21(6):593.
Hyperthyroidism (thyrotoxicosis). Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/thyroid-disorders/hyperthyroidism. Accessed May 17, 2019.
Hyperthyroidism and other causes of thyrotoxicosis. EBSCO DynaMed website. Available at: https://www.dynamed.com/topics/dmp~AN~T116479/Hyperthyroidism-and-other-cause...f-thyrotoxicosis. Updated November 1, 2018. Accessed May 17, 2019.
Primary hyperthyroidism. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: http://www.niddk.nih.gov/health-information/health-topics/endocrine/primary-hyperparathyroidism/Pages/fact-sheet.aspx. Updated March 2019. Accessed May 17, 2019.
Thyroid disorders. Healthy Women website—National Women's Health Resource Center website. Available at: http://www.healthywomen.org/condition/thyroid-disorders. Accessed May 17, 2019.
Last reviewed March 2019 by EBSCO Medical Review BoardJames P. Cornell, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
