Goiter
Enlargement of the THYROID GLAND that may increase from about 20 grams to hundreds of grams in human adults. Goiter is observed in individuals with normal thyroid function (euthyroidism), thyroid deficiency (HYPOTHYROIDISM), or hormone overproduction (HYPERTHYROIDISM). Goiter may be congenital or acquired, sporadic or endemic (GOITER, ENDEMIC).
Goiter, Nodular
An enlarged THYROID GLAND containing multiple nodules (THYROID NODULE), usually resulting from recurrent thyroid HYPERPLASIA and involution over many years to produce the irregular enlargement. Multinodular goiters may be nontoxic or may induce THYROTOXICOSIS.
Goiter, Endemic
A form of IODINE deficiency disorders characterized by an enlargement of the THYROID GLAND in a significantly large fraction of a POPULATION GROUP. Endemic goiter is common in mountainous and iodine-deficient areas of the world where the DIET contains insufficient amount of iodine.
Goiter, Substernal
An enlarged THYROID GLAND with at least 50% of the gland situated behind the STERNUM. It is an unusual presentation of an intrathoracic goiter. Substernal goiters frequently cause compression on the TRACHEA leading to deviation, narrowing, and respiratory symptoms.
Iodine
Thyroid Gland
A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.
Thyroidectomy
Surgical removal of the thyroid gland. (Dorland, 28th ed)
Thyroid Diseases
Pathological processes involving the THYROID GLAND.
Hyperthyroidism
Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE.
Thyrotropin
A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.
Graves Disease
A common form of hyperthyroidism with a diffuse hyperplastic GOITER. It is an autoimmune disorder that produces antibodies against the THYROID STIMULATING HORMONE RECEPTOR. These autoantibodies activate the TSH receptor, thereby stimulating the THYROID GLAND and hypersecretion of THYROID HORMONES. These autoantibodies can also affect the eyes (GRAVES OPHTHALMOPATHY) and the skin (Graves dermopathy).
Thyroid Neoplasms
Tumors or cancer of the THYROID GLAND.
Antithyroid Agents
Agents that are used to treat hyperthyroidism by reducing the excessive production of thyroid hormones.
Thyroiditis
Inflammatory diseases of the THYROID GLAND. Thyroiditis can be classified into acute (THYROIDITIS, SUPPURATIVE), subacute (granulomatous and lymphocytic), chronic fibrous (Riedel's), chronic lymphocytic (HASHIMOTO DISEASE), transient (POSTPARTUM THYROIDITIS), and other AUTOIMMUNE THYROIDITIS subtypes.
Thyroglobulin
Thyroglobulin is a glycoprotein synthesized and secreted by thyroid follicular cells, serving as a precursor for the production of thyroid hormones T3 and T4, and its measurement in blood serves as a tumor marker for thyroid cancer surveillance.
Lingual Goiter
Pathological enlargement of the LINGUAL THYROID, ectopic thyroid tissue at the base of the TONGUE. It may cause upper AIRWAY OBSTRUCTION; DYSPHAGIA; or HYPOTHYROIDISM symptoms.
Thyrotoxicosis
A hypermetabolic syndrome caused by excess THYROID HORMONES which may come from endogenous or exogenous sources. The endogenous source of hormone may be thyroid HYPERPLASIA; THYROID NEOPLASMS; or hormone-producing extrathyroidal tissue. Thyrotoxicosis is characterized by NERVOUSNESS; TACHYCARDIA; FATIGUE; WEIGHT LOSS; heat intolerance; and excessive SWEATING.
Thyroxine
The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.
Hypothyroidism
A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA.
Thyroiditis, Autoimmune
Inflammatory disease of the THYROID GLAND due to autoimmune responses leading to lymphocytic infiltration of the gland. It is characterized by the presence of circulating thyroid antigen-specific T-CELLS and thyroid AUTOANTIBODIES. The clinical signs can range from HYPOTHYROIDISM to THYROTOXICOSIS depending on the type of autoimmune thyroiditis.
Thyroid Function Tests
Blood tests used to evaluate the functioning of the thyroid gland.
Thyroid Hormones
Potassium Iodide
An inorganic compound that is used as a source of iodine in thyrotoxic crisis and in the preparation of thyrotoxic patients for thyroidectomy. (From Dorland, 27th ed)
Iodine Radioisotopes
Congenital Hypothyroidism
A condition in infancy or early childhood due to an in-utero deficiency of THYROID HORMONES that can be caused by genetic or environmental factors, such as thyroid dysgenesis or HYPOTHYROIDISM in infants of mothers treated with THIOURACIL during pregnancy. Endemic cretinism is the result of iodine deficiency. Clinical symptoms include severe MENTAL RETARDATION, impaired skeletal development, short stature, and MYXEDEMA.
Recurrent Laryngeal Nerve Injuries
Thyroiditis, Subacute
Spontaneously remitting inflammatory condition of the THYROID GLAND, characterized by FEVER; MUSCLE WEAKNESS; SORE THROAT; severe thyroid PAIN; and an enlarged damaged gland containing GIANT CELLS. The disease frequently follows a viral infection.
Iodine Compounds
Inorganic compounds that contain iodine as an integral part of the molecule.
Iodized Oil
A preparation of oil that contains covalently bound IODINE. It is commonly used as a RADIOCONTRAST AGENT and as a suspension medium for CHEMOTHERAPEUTIC AGENTS.
Triiodothyronine
A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.
Adenocarcinoma, Follicular
An adenocarcinoma of the thyroid gland, in which the cells are arranged in the form of follicles. (From Dorland, 27th ed)
Iodides
Inorganic binary compounds of iodine or the I- ion.
Iodide Peroxidase
A hemeprotein that catalyzes the oxidation of the iodide radical to iodine with the subsequent iodination of many organic compounds, particularly proteins. EC 1.11.1.8.
Carcinoma, Papillary
Tracheal Stenosis
Methimazole
A thioureylene antithyroid agent that inhibits the formation of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin. This is done by interfering with the oxidation of iodide ion and iodotyrosyl groups through inhibition of the peroxidase enzyme.
Guaiacol
Carcinoma, Papillary, Follicular
Immunoglobulins, Thyroid-Stimulating
Autoantibodies that bind to the thyroid-stimulating hormone (TSH) receptor (RECEPTORS, THYROTROPIN) on thyroid epithelial cells. The autoantibodies mimic TSH causing an unregulated production of thyroid hormones characteristic of GRAVES DISEASE.