Definition:
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. See also:
Alternative Names:
Myxedema; Adult hypothyroidism
Causes, incidence, and risk factors:
The thyroid gland is located in the front of the neck just below the voice box (larynx). It releases hormones that control metabolism. The most common cause of hypothyroidism is inflammation of the thyroid gland, which damages the gland's cells. Autoimmune or Hashimoto's thyroiditis, in which the immune system attacks the thyroid gland, is the most common example of this. Some women develop hypothyroidism after pregancy (often referred to as "postpartum throiditis"). Other common causes of hypothyroidism include: Congenital (birth) defects Radiation treatments to the neck to treat different cancers, which may also damage the thyroid gland Radioactive iodine used to treat an overactive thyroid (hyperthyroidism) Surgical removal of part or all of the thyroid gland, done to treat other thyroid problems Viral thyroiditis, which may case hyperthyroidism and is often followed by temporary or permanent hypothyroidism
Certain drugs can cause hyperthyroidism, including: Risk factors include: Age over 50 years Being female
References:
Fatourechi V. Subclinical hypothyroidism: an update for primary care physicians. Mayo Clin Proc. 2009;84(1):65-71. Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Goldman: Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders; 2007:chap 244. Vaidya B, Pearce SH. Management opf hypothyroidism in adults. BMJ. 2008;28;337:a801.
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