Causes of elevated thyroid-stimulating hormone
| Subclinical hypothyroidism Autoimmune (Hashimoto) thyroiditis Suboptimal treatment of overt hypothyroidism Partial thyroidectomy Radioactive iodine ablation External beam radiation of head and neck Infiltrative diseases of the thyroid (amyloidosis, sarcoidosis, hemochromatosis, Riedel thyroiditis, scleroderma) Drugs, eg, iodine contrast, amiodarone, lithium, tyrosine kinase inhibitors (sunitinib, sorafenib), interferon alpha, or immune response modulators (ipilimumab, alemtuzumab, pembrolizumab) Iodine deficiency Excess iodine Thyroid dysgenesis |
| Physiologic increases Diurnal variation Recovery phase of euthyroid sick syndrome Recovery phase of subacute, painless, or postpartum thyroiditis |
| Other causes Assay variability Substances that interfere with TSH assays (heterophile antibodies, rheumatoid factor, biotin, macro-TSH or abnormal TSH isoforms) Central hypothyroidism or hyperthyroidism Thyroid hormone resistance Impaired renal function Adrenal insufficiency Obesity Older age |
Based on information in references 1, 2, and 16.