Thyroid Gland Central Dysfunction
(continued)

What is Thyroid Disease?

Thyroid disease is caused by a breakdown in this chain of hormonal events. There are many different specific types of thyroid diseases, benign (non-cancerous) and malignant (cancerous).There are many different specific disorders in each category. We will focus on two general categories of non-cancerous thyroid conditions: hyperthyroidism (over active thyroid) and hypothyroidism (under active thyroid).

Thyroid disease in general affects nearly 13 million Americans. Women are affected five to eight times more frequently than men. The good news about thyroid disease is that reliable diagnostic and treatment options are readily available; when properly treated, patients with thyroid disorders can generally lead normal, active lives. The bad news about thyroid disease is that nearly half of affected adults remain undiagnosed despite having fairly typical symptoms. If untreated, thyroid disorders may cause cardiovascular problems, infertility, osteoporosis, and damage to major organs.

Hyperthyroidism affects approximately 1 of every 100 American adults. In patients with hyperthyroidism, the thyroid produces abnormally high levels of thyroid hormones. This causes the body to burn energy faster than normal and speed up many vital functions. In most cases, hyperthyroidism is due to a problem in the thyroid gland itself. The most common causes for this include Grave's disease and a benign thyroid tumor that secretes increased and uncontrolled amounts of thyroid hormones. Short-term hyperthyroidism may also result from certain types of thyroid inflammation or viral infections. Very rarely, hyperthyroidism may be caused by overproduction of thyroid-stimulating hormone (TSH) by the pituitary gland or by production of excess thyroid hormone from a source outside the thyroid, such as from an ovarian tumor.

Graves' disease is the most common cause of hyperthyroidism. This is the form of thyroid disease that affected Gail Devers, as well as former first lady Barbara Bush. It is an autoimmune disorder, in which an antibody against the thyroid's TSH receptor disrupts the thyroid's local regulation of hormone secretion causing excessive thyroid hormone production. It usually affects young women between ages 20 and 40 (although about 12% of patients are men).

Graves' disease is also known as "diffuse toxic goiter". It is characterized by clinical hyperthyroidism AND one or more of the following: goiter (a visibly or palpably enlarged thyroid gland protruding from the neck), exophthalmos (protruding eyes which appear enlarged), and pretibial myxedema (a type of swelling in the front parts of the lower legs). Graves' disease has a chronic course with remissions and relapses, so it sometimes is difficult to diagnose.

Treatment of Graves' disease is similar to the treatment of hyperthyroidism. Generally, medical treatment is offered first with antithyroid drugs (e.g. propythioruacil and methimazole), but only 16% to 40% of patients remain in remission after discontinuing therapy. For those who relapse, radioactive iodine therapy is recommended. About 1 in 4 patients will become hypothyroid as a result of therapy within one year, and the incidence will continue to increase yearly. Thus, many Graves' disease patients will actually wind up with hypothyroidism and rely on thyroid replacement medicine on a regular basis.

Surgical treatment is also indicated for younger patients with Graves' disease who have relapsed after antithyroid drug therapy, patients who have large goiters, patients who can't tolerate medical therapy, and some others. Generally, patients do well, but as with any surgery, there is a risk for complications. Surgery can be complete (resulting in hypothyroidism and need for thyroid replacement medicine) or partial.