Causes for Increased Thyroxine or Free Thyroxine Values (cont.)
Primary hyperthyroidism (T4/T3) type)
Severe TBG elevation; some patients with some FT4 kits
Excess therapy of hypothyroidism
Synthroid in adequate dose; some patients
Active thyroiditis (subacute, painless, early active Hashimotoís disease); some patients
Familial dysalbuminemic hyperthyroxinemia (some FT4 kits, esp. analog types)
Peripheral resistance to T4 syndrome
Aminodarone or propranolol; some patients
Postpartum transient toxicosis
Factitious hyperthyroidism
Jod-Basedow (iodine-induced) hyperthyroidism
Severe nonthyroid illness, occasional patients