Types of Thyroid Disease

The American Thyroid Association estimates that millions of Americans suffer from some type of thyroid disorder or disease. The thyroid, a small, butterfly-shaped gland found inside the throat, is responsible for controlling your body's metabolism, or use of energy.

Common Types

• There are two major types of thyroid disease: hyperthyroidism and hypothyroidism. Hyperthyroidism is when thyroid manufactures too much of its hormones while lowered hormone production by the thyroid causes hypothyroidism.

Symptoms

• Symptoms of hyperthyroidism include accelerated heart rate, weight loss, hand tremors and sensitivity to light. Hypothyroidism symptoms include weight gain, fatigue, decreased memory and water retention.

Common Causes

• Graves' Disease is a common cause of hyperthyroidism, while a common cause of hypothyroidism is Hashimoto's Thyroiditis. In both Graves' Disease and Hashimoto's Thyroiditis, a person's immune system attacks the thyroid itself, and the inflamed thyroid produces too much or too little of its hormones.

Rare Types

• Goiters, enlarged thyroid glands caused by a lack of iodine in the diet, slow the production of thyroid hormones and cause hypothyroidism. Thyroiditis--a side-effect of other diseases or infections, or exposure to toxic chemicals--and thyroid cancers can cause either hypo- or hyperthyroidism.

Prevalence

• Leonard Wartofsky, chairman of the Department of Medicine at Washington Hospital Center, indicates that thyroid disease is affects women five times more often than men.