Worldwide, the most common cause for<unk>  is iodine deficiency, commonly seen in countries that scarcely 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.<unk>  can also result from cyanide poisoning, which is particularly common in tropical countries where people eat the cyanide-rich cassava root as the staple food. 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<unk>  worldwide Increased size of thyroid may be permanent if untreated for around five years Congenital hypothyroidism Inborn errors of thyroid hormone synthesis Hypothyroidism<unk> gen ingestion Adverse drug reactions Hashimoto's thyroiditis Autoimmune disease in which the thyroid gland is gradually destroyed. Infiltration of lymphocytes. 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 Will develop in about 0.5% of males and 3% of females 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, Symptomatic hypothyroidism Diffuse * Sarcoidosis * Amyloidosis * Hydatidiform mole * Cysts * Acromegaly * Pendred syndrome
Goitre
Pseudo-goitre
Endemic goitre
Thyroid nodule
Thymoma
Thyroiditis
Airsickness
Iron lung