Condition	Characteristics
Graves' disease	Diffuse thyroid gland enlargement; hypermetabolism; elevated free T4 level, low TSH level, elevated thyroid autoantibody level; increased radioactive iodine uptake
Subacute granulomatous thyroiditis (de Quervain's thyroiditis)	Painful enlargement of the thyroid gland; hypermetabolism; elevated free T4 level, low TSH level; decreased radioactive iodine uptake
Acute suppurative thyroiditis	Fever, painful mass in one thyroid gland lobe; normal thyroid function tests and radioactive iodine uptake
Toxic adenoma	Solitary thyroid nodule; hypermetabolism; lack of ocular changes; elevated free T4 level, low TSH level
Chronic lymphocytic thyroiditis (Hashimoto's disease)	Diffuse enlargement of the thyroid gland with or without clinical features of hypometabolism; normal thyroid function tests or low free T4 level, elevated thyroid autoantibody level