Goitre - Causes

Causes

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.

Cause	Pathophysiology	Resultant thyroid activity	Growth pattern	Treatment	Incidence and prevalence	Prognosis
Iodine deficiency	Hyperplasia of thyroid to compensate for decreased efficacy	Can cause hypothyroidism	Diffuse	Iodine	Constitutes over 90% cases of goitre worldwide	Increased size of thyroid may be permanent if untreated for around five years
Congenital hypothyroidism	Inborn errors of thyroid hormone synthesis	Hypothyroidism
Goitrogen ingestion
Adverse drug reactions
Hashimoto's thyroiditis	Autoimmune disease in which the thyroid gland is gradually destroyed	Hypothyroidism	Diffuse and lobulated	Thyroid hormone replacement	Prevalence: 1 to 1.5 in a 1000	Remission with treatment
Pituitary disease	Hypersecretion of thyroid stimulating hormone, almost always by a pituitary adenoma		Diffuse	Pituitary surgery	Very rare
Graves' disease—also called Basedow syndrome	Autoantibodies (TSHR-Ab) that activate the TSH-receptor (TSHR)	Hyperthyroidism	Diffuse	Antithyroid agents, radioiodine, surgery	1 to 2 cases per 1,000 population per year	Remission with treatment, but still lower quality of life for 14 to 21 years after treatment, with lower mood and lower vitality, regardless of the choice of treatment
Thyroiditis	Acute or chronic inflammation	Can be hyperthyroidism initially, but progress to hypothyroidism
Thyroid cancer			Usually uninodular			Overall relative 5-year survival rate of 85% for females and 74% for males
Benign thyroid neoplasms		Usually hyperthyroidism	Usually uninodular			Mostly harmless
Thyroid hormone insensitivity		Secretional hyperthyroidism, Symptomatical hypothyroidism	Diffuse

Sarcoidosis
amyloidosis
hydatidiform mole
cysts
acromegaly