Hyperthyroidism is a disease in which the thyroid gland produces too much thyroid hormone. The thyroid gland is a butterfly-shaped gland in the front of the neck. It produces hormones that control metabolism. The most common form of hyperthyroidism is Graves' disease.
Graves' disease occurs when your own immune system produces antibodies that stimulate overproduction of thyroid hormone. Other common causes of hyperthyroidism include:
Thyroid nodules or tumors
Toxic uninodular goiter—a single nodule in the thyroid gland
Subacute thyroiditis—inflammation of the thyroid gland (often later leads to
hypothyroidism
)
Toxic multinodular goiter—multiple areas in the thyroid gland which overproduce excess amount of thyroid hormone
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
The doctor will ask about your symptoms and medical and family history, and perform a physical exam. The exam usually reveals the following:
Enlarged thyroid gland
Rapid pulse
Warm, moist skin
Several of the symptoms listed above
Blood tests will be ordered to confirm the diagnosis, including:
Thyroid stimulating hormone (TSH), currently the best screening test
Free T4 and free T3
Thyroid autoantibodies (TSH receptor antibody)
Additionally, a test called a thyroid scan may be needed to help differentiate between Graves' disease and other causes of hyperthyroidism. Your doctor will most likely order a radioactive iodine uptake test, which measures how active your thyroid is in taking up the iodine. Occasionally, a
needle biopsy
of the thyroid is needed.
Treatment
Treatment will depend on:
Age
Severity of symptoms
Cause of hyperthyroidism
Pregnancy status
Treatment options include:
Antithyroid Drugs
Best suited for Graves' disease, antithyroid drugs (methimazole, propylthiouracil) suppress thyroid synthesis. If the disease goes into remission, you may no longer need the medication.
Radioactive Iodine
This is the most commonly used definitive treatment in the US. Radioactive iodine is taken orally and absorbed by the thyroid gland where it damages most of the thyroid cells. The damaged cells can no longer produce thyroid hormones. Within days, the excess radioactive iodine either passes out of the body in the urine or changes into a nonradioactive state. Eventually, you will need to take a daily thyroid replacement.
Surgery
Surgical treatment is rarely used in the treatment of hyperthyroidism except in young children, pregnant women, and those individuals with a very large goiter that causes either swallowing or breathing problems. Most patients take antithyroid medication prior to surgery. If the surgery leaves you with too little production of thyroid hormone, you will need to take a daily thyroid supplement.
Beta-blockers
Until the treatments above take effect, you may need to take beta-blockers (eg, propranolol, atenolol, metoprolol) to relieve rapid heart rate and jitters.
Eye Protection
If there are eye symptoms, eye protection before sleep, artificial tears, and sunglasses will be prescribed by your doctor.
Prevention
There are several ways to prevent getting hyperthyroidism including:
Eat a diet with an adequate amount of iodine.
Get regular screening for hyperthyroidism if there is someone in your immediate family with this disease or you have another autoimmune disease.
RESOURCES:
The
American Thyroid Association http://www.thyroid.org
National Graves' Disease Foundation http://www.ngdf.org
CANADIAN RESOURCES
Health Canada http://www.hc-sc.gc.ca/index_e.html
Thyroid Foundation of Canada http://www.thyroid.ca
References:
American Association of Clinical Endocrinologists. Medical guidelines for clinical practice for the evaluation and treatment of hyperthyroidism and hypothyroidism.
Endocrine Practice
. 2002;8:457-469.
American Association of Clinical Endocrinologists website. Available at:
http://www.aace.com/
.
Graves' disease.
N Engl J Med
. 2000 Oct 26.
To ft AD. Subclinical hyperthyroidism.
N Engl J Med
. 2001;345:512-516.
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;148:229-237.
Woeber K. Update on the management of hyperthyroidism and hypothyroidism.
Arch Intern Med
. 2000;160:1067-1071.
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.
