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Thyroid diseases

  • Definition

    The thyroid gland is located in the front of the neck, just below the voice box (larynx). It produces chemicals (hormones) that help the body control metabolism. Thyroid hormone is normally produced in response to another hormone released by the pituitary gland.

    There are four main types of thyroid disease:

    • Hyperthyroidism -- too much thyroid hormone
    • Hypothyroidism -- too little thyroid hormone
    • Benign (noncancerous) 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)
    • Congenital goiter
    • Goiter
    • Hyperthyroidism
    • Hypopituitarism
    • Hypothyroidism
    • Medullary thyroid carcinoma
    • Multiple endocrine neoplasia (MEN) II
    • Painless (silent) thyroiditis
    • Papillary carcinoma of the thyroid
    • Subacute thyroiditis
    • Thyroid cancer
    • Toxic nodular goiter

    Causes, incidence, and risk factors