HYPERTHYROIDISM

Grave's disease [75-80%; = 'diffuse toxic goitre'; 'autoimmune'; diffuse enlargement of gland usually present]

toxic multinodular goitre [20-25%]

single toxic nodule [1-2%; adenoma]

functioning carcinoma [1%]

pituitary TSH adenoma [<1%; may arise following prolonged hypothyroidism]

factitious [self-administration of thyroxine]

subacute or chronic thyroiditis (usually cause hypothyroidism)

neonatal hyperthyroidism (infant of mother having Grave's disease)