The thyroid gland is located in the base of the neck on both sides of the lower part of the voice box (larynx) and upper part of the wind pipe (trachea). The thyroid produces chemicals (hormones) that help the body control metabolism. Thyroid hormone is also produced in response to another hormone secreted by the pituitary gland.

There are four main types of thyroid disease:

• Hyperthyroidism -- too much thyroid hormone
• Hypothyroidism -- too little thyroid hormone
• Benign (non-cancerous) thyroid disease
• Thyroid cancer

For information about a specific type of thyroid disease see one of the following:

• Anaplastic carcinoma of the thyroid
• Chronic thyroiditis (Hashimoto's disease)
• Colloid nodular goiter
• Hyperthyroidism
• Hypopituitarism
• Hypothyroidism
• Hypothyroidism - primary
• Hypothyroidism - secondary
• Medullary thyroid carcinoma
• Multiple endocrine neoplasia (MEN) II
• Painless (silent) thyroiditis
• Papillary carcinoma of the thyroid
• Subacute thyroiditis
• Thyroid cancer
• Congenital goiter