Population	Nonpregnant, asymptomatic adults
Recommendation	No recommendation
	Grade: I statement (insufficient evidence)
Risk assessment	Risk factors for an elevated thyroid-stimulating hormone (TSH) level include female sex, advancing age, white race, type 1 diabetes, Down syndrome, family history of thyroid disease, goiter, previous hyperthyroidism, and external-beam radiation in the head and neck area. Risk factors for a low TSH level include female sex; advancing age; black race; low iodine intake; personal or family history of thyroid disease; and ingestion of iodine-containing drugs, such as amiodarone.
Screening tests	The primary screening test for thyroid dysfunction is serum TSH testing. Multiple tests over 3 to 6 mo should be performed to confirm or rule out abnormal findings. Follow-up testing of serum thyroxine (T4) levels in persons with persistently abnormal TSH levels can differentiate between subclinical (normal T4) and “overt” (abnormal T4) thyroid dysfunction.
Treatment and interventions	Hypothyroidism is treated with oral T4 monotherapy (levothyroxine sodium). Consensus is lacking on the appropriate point for clinical intervention, especially for TSH levels < 10.0 mIU/L. Hyperthyroidism is treated with antithyroid medications (e.g., methimazole) or nonreversible thyroid ablation therapy (e.g., radioactive iodine or surgery). Treatment is generally recommended for patients with a TSH level that is undetectable or < 0.1 mIU/L, particularly those with overt Graves disease or nodular thyroid disease.
Balance of benefits and harms	The current evidence is insufficient to assess the balance of benefits and harms of screening for thyroid dysfunction in nonpregnant asymptomatic adults.