Abnormality of thyroid physiology Impaired sensitivity to thyroid hormone Impaired sensitivity to thyroid hormone may be accompanied by goiter and no clear symptoms and signs of thyrotoxicosis. The etiologies of this feature include defects in the thyroid hormone receptor, reduced cellular access of the biologically active thyroid hormone, T3 related to defects of thyroid hormone cell membrane transport, and a defect reducing the intracellular metabolism generating T3 from T4. Elevated serum levels of free thyroid hormone with nonsuppressed TSH HP:0008215 Thyroid hormone receptor defect End-organ unresponsiveness to thyroid hormone SNOMEDCT_US:111567006 HP:0008243 SNOMEDCT_US:50375007 HP:0008262 SNOMEDCT_US:237560005 SNOMEDCT_US:237559000 UMLS:C2940786 HP:0002930 Thyroid hormone resistance Reduced sensitivity of end organs to thyroid hormone characterized by elevated serum levels of free thyroid hormone with nonsuppressed thyroid stimulating hormone. Resistance to thyroid hormone