HYPERTHYROIDISM 

What is hyperthyroidism?

Hyperthyroidism is a state in what the thyroid gland becomes overactive. It is caused by several conditions. Graves' disease, the most common cause of hyperthyroidism (over-active thyroid), is an autoimmune disorder which causes the body to manufacture and secrete excessive amounts of thyroid hormone, resulting in an increased metabolic rate. The disease is named for the 19th-century Irish physician, Robert Graves, who first recognized the disease.

Other reasons for hyperthyroidism include hyperactive thyroid nodules, de Quervain's thyroiditis, taking too much thyroid supplements, and exposure to certain drugs or chemicals.

How many people suffer from Graves' disease?

In the United States, Graves' disease afflicts approximately one million people.

Who is at risk for developing Graves' disease?

While the cause(s) of Graves' are unknown, the condition is sometimes familial, which means heredity may play a role in who develops the disease. Evidence also suggests that physical or emotional stress may be a factor in the onset of Graves' disease. Women in their thirties and forties appear to be especially vulnerable. Statistically, women are 15-20 times more likely than men to develop Graves' disease.

What are the symptoms of Graves' disease?

The disease is characterized by increased heart rate, heat intolerance, weight loss (often with increased appetite), diarrhea or more frequent-than-usual bowel movements, headache, restless over- activity, heavy sweating, irritability, bad temper, irregular menstrual periods, sleeplessness and weakness. Patients may also experience some of the eye changes associated with Graves' disease, including burning, dryness, eye protrusion, double vision and lid retraction.

Is hyperthyroidism easy to diagnose?

Yes. If your physician orders the right series of blood tests, the condition is easily diagnosed. Unfortunately, because of the similarity of the symptoms, patients suffering from Graves' disease are sometimes mistakenly diagnosed as suffering from anxiety, depression, and stress-related exhaustion. A thyroid panel of blood tests, however, can easily distinguish these conditions from hyperthyroidism.

What sort of treatments are available for Graves' disease?

There are three methods of treatment currently available for treating Graves' disease: antithyroid drugs, radioiodine therapy and surgery.

What are antithyroid drugs?

Antithyroid drugs interfere with the formation of thyroxine (thyroid hormone) by blocking the organic binding of iodine, thereby causing the symptoms of hyperthyroidism to subside. The antithyroid drugs most commonly in use today are propylthiouracil (PTU) and carbimazole (or methimazole). In addition, your physician may also prescribe a "beta blocker" called propranolol to help allay the increased pulse rate associated with hyperthyroidism.

How often and for how long must I take antithyroid medication?

Dosages of antithyroid drugs are tailored to the needs of each patient. Some patients will thus take more medication, while others will take less. Your endocrinologist will set the correct dosage upon diagnosis and adjust it as necessary throughout your regimen of therapy depending on your hormone results. Length of treatment will likewise vary from patient to patient. Although hormone levels usually return to normal in about two to three months, most patients are kept on drug therapy for eighteen months, others for two years. Once a patient becomes euthyroid; that is, once the manufacturing of thyroid hormone becomes controlled to acceptable levels (usually by two to three months), the patient's dose will generally be cut back to a smaller, "maintenance" dose. Antithyroid drugs are very safe to take; a very small number of patients may develop a mild rash.

Will beta-blockers alone make me better?

No! While beta-blockers control some symptoms of hyperthyroidism, they will do little to treat the underlying disease. Taking beta-blockers alone can be extremely dangerous, in fact, as they can mask the symptoms of Graves' disease while the disease steadily worsens. For this reason, they should be taken in conjunction with antithyroid drugs. Your doctor will advise on this.

What is radioiodine therapy?

Radioiodine is another method of treating Graves' disease. Radioiodine is administered by mouth, usually in liquid form. When given in a sufficient dose, it irradiates the cells that participate in the Graves' disease process.

Is radioiodine therapy safe?

Data compiled thus far from more than fifty years suggests that it is. Radioiodine has been used to treat hyperthyroidism since 1948, and doctors regard it as a safe and effective means of treating Graves' disease. A few doctors, however, still prefer to restrict its use to patients beyond childbearing age. Radioiodine is always contraindicated during pregnancy. Women are advised to avoid pregnancy for at least six months after taking radioiodine. It is usually a one-time treatment. It is usually given to patients who relapse after a course of drug treatment.

What about surgery?

In some instances, patients and their doctors may feel that Graves' disease can be best treated by surgery to remove most of the thyroid gland. While generally effective, surgery is expensive and, in some instances, risky. Surgery is thus usually reserved for those patients who are unable to take antithyroid drugs and who refuse radioiodine treatment.

What's this about Graves' disease affecting the eyes?

In some patients, ophthalmopathy (eye changes) are an unfortunate effect of Graves' disease. These changes may precede, accompany or follow thyrotoxicosis and can include light sensitivity, excessive tearing, proptosis (protrusion of one or both eyes), pain, swelling of the eye-lids, diplopia (double vision), dryness, and loss of visual acuity. There is no definitive therapy for these eye changes. However, some patients have found methylcellulose eyedrops, a low-sodium diet, and elevating their heads while sleeping to be helpful. Steroid therapy may be therapeutic in particularly bad cases, as may radiation therapy to the posterior portion of the eye and surgical decompression. Fortunately, such severe cases are rare.

Didn't George Bush have Graves' disease?

Yes, former U.S. President George Bush suffered from the disease while he was president, as did his wife Barbara. Statistically, in fact, the Bushes are something of a medical marvel. Graves’ disease is rarer in men than in women. It is nearly unheard of for a husband and wife to both suffer from Graves' disease.

Complications of Graves' disease

In patients who have multiple successive relapses, there is a risk of developing heart failure. Also if the hyperactivity is very severe, the patient may develop a rare state called thyroid crisis. The latter is characterized by confusion, elevated temperatures, changes in conscious level, heart problems. It is a serious medical emergency and treatment in an intensive care setting is usually recommended.

Treatment of Graves' disease during pregnancy

Patients with Graves' disease are often women in their reproductive years. If hyperthyroidism develops during pregnancy, it is safe to continue antithyroid drugs. Drug treatment is needed to stabilize the condition and reduce the risk of a miscarriage. Often during the last trimester of pregnancy, the hyperthyroidism disappears and drug treatment may be safely discontinued. However there is a significant risk of relapse following delivery of the baby.

It is usually safe to breastfeed while continuing antithyroid drug treatment.