Hyperthyroidism

Overview

Many of your symptoms of hyperthyroidism relate to increased metabolic activity. They include:

• Intolerance of heat
• Increased sweating
• Weight loss
• High blood pressure
• Abnormal heart rhythm (arrhythmia)
• Thinning of the skin
• Nervousness
• Difficulty sleeping
• Fatigue

In some cases, you have few, if any, symptoms (called subclinical hyperthyroidism). If you have subclinical hyperthyroidism, you may still have an increased risk of a type of irregular heartbeat called atrial fibrillation or, if you are a woman, decreased bone density.

Additionally, older people sometimes develop apathetic hyperthyroidism, where they don’t have many of the classic symptoms. In such cases, weight loss, irregular heart rhythm, depression and lethargy can signal it.

Causes

Hyperthyroidism affects more women than men. Causes of hyperthyroidism can include:

• Graves’ disease. This autoimmune condition overstimulates the thyroid gland.
• Viral infection. Hyperthyroidism sometimes develops following infection with influenza or mumps. This condition tends to resolve itself after a few weeks.
• Thyroid nodules. Abnormal growths on the thyroid gland, called thyroid nodules, can produce excess thyroid hormones.
• Medicine. Some drugs can cause hyperthyroidism including lithium, also used to treat bipolar disorder, and interferon-alpha, also used to treat hepatitis.
• Thyroid hormone medicine. Taking too much of this medicine, used to treat an underactive thyroid gland (hypothyroidism), can lead to symptoms of hyperthyroidism.

Treatment

Your IU Health physicians will recommend prompt and thorough evaluation and treatment of hyperthyroidism because of the risks it poses for the heart and other organs. If the condition causes you to have an irregular heart rhythm (atrial fibrillation), your chance of having a stroke increases.

Fortunately, with proper treatment, you can generally control or cure hyperthyroidism. Your team will first identify the reason for your overactive thyroid, drawing on their extensive experience as well as advanced diagnostic technology.

They will then recommend treatment based on factors such as the severity and prognosis of your case as well as your age and general health. Your team will consist of other physicians, such as surgeons and other specialists whenever necessary to deliver comprehensive care. Their partnership with the Indiana University School of Medicine ensures that you have access to the latest innovations in diagnosis and treatment.

In treating hyperthyroidism, your physicians will want to return your hormone levels to normal, although certain mild cases might only need observation. Treatment options for hyperthyroidism include:

• Antithyroid medicine. Certain medicines, particularly methimazole, disrupt production of thyroid hormones. You take methimazole as a pill between one and three times each day. Symptoms often go away after six to 12 weeks, but you typically continue treatment for a year or more before tapering your dose. This treatment does not cause permanent damage to the gland. Some patients never experience hyperthyroidism again after taking this medicine, but others have a relapse.
• Radioactive iodine. This medicine, typically taken in pill form, partially or completely destroys the thyroid gland to reduce or eliminate thyroid hormone production. You typically need only one dose, which takes effect within six months. While generally safe, pregnant women should not take it because it may damage the developing fetus. After you take radioactive iodine, you receive guidelines to avoid exposing other people to radiation. For example, you should avoid close contact with family members and keep your toilet especially clean for several days until most of the medicine clears from your system. Radioactive iodine often causes the thyroid to become underactive (hypothyroidism), so you may need hormone replacement therapy after treatment.
• Surgery. Partial or complete removal of the thyroid gland stops excess thyroid hormone production. You receive general anesthesia for this surgery, which often takes between two and four hours. The most common procedure involves a cut several inches long across the front of your neck. You may require lifelong hormone replacement therapy if your surgeon removes your entire thyroid gland.
• Beta blockers. These medicines control some hyperthyroidism symptoms, including rapid heartbeat and anxiety. Normally used to treat high blood pressure (hypertension) , they help you feel more comfortable while waiting for other therapies to work. They do not influence hyperthyroidism directly.
• Steroids. When hyperthyroidism develops from a viral infection, corticosteroids such as prednisone can help reduce inflammation of the gland.