Drugs that alter thyroid test
amiodarone (Cordarone) aspirin cimetidine (Tagamet) diazepam (Valium) furosemide (Lasix) heparin lithium (Lithotabs) phenytoin (Dilantin) and other anticonvulsants propranolol (Inderal)
hyperthyroidism risk factors
Preexisting goiter Recent infection or trauma Immigration from iodine-deficient area Medications like synthroid Family history of thyroid