Goiter

Goitre
Diffuse hyperplasia of the thyroid
Classification and external resources
Specialty	Endocrinology
ICD-10	E01-E05
ICD-9-CM	240.9
DiseasesDB	5332
MedlinePlus	001178
MeSH	D006042
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A goitre (British English) or goiter (American English) (from the Latin gutteria) is a swelling of the neck or larynx resulting from enlargement of the thyroid gland (thyromegaly), associated with a thyroid gland that is not functioning properly.

Worldwide, over 90% cases of goitre are caused by iodine deficiency.

Goitre, associated with hypothyroidism or hyperthyroidism, may be present with symptoms of the underlying disorder. For hyperthyroidism, the most common symptoms are associated with adrenergic stimulation: tachycardia, palpitations, nervousness, tremor, increased blood pressure and heat intolerance. Clinical manifestations are often related to hypermetabolism, (increased metabolism), excessive thyroid hormone, an increase in oxygen consumption, metabolic changes in protein metabolism, immunologic stimulation of diffuse goitre, and ocular changes (exophthalmos). Hypothyroid individuals may have weight gain despite poor appetite, cold intolerance, constipation and lethargy. However, these symptoms are often non-specific and make diagnosis difficult.

Regarding morphology, goitres may be classified either as the growth pattern or as the size of the growth:

Goitre (Class II)

Goitre with autonomous adenoma

Goitre Class III

Worldwide, the most common cause for goitre is iodine deficiency, usually seen in countries that do not use iodized salt. Selenium deficiency is also considered a contributing factor. In countries that use iodized salt, Hashimoto's thyroiditis is the most common cause. Goitre can also result from cyanide poisoning; this is particularly common in tropical countries where people eat the cyanide-rich cassava root as the staple food.

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