Elevated TSH
July 29th, 2019
Overview
An elevated TSH is suggestive of primary hypothyroidism.
Causes of Elevated TSH
Primary Hypothyroidism
- Autoimmune thyroiditis - Hashimoto's, atrophic
- Hypothyroid phase of thyroiditis
- Iatrogenic - radioiodine therapy, thyroidectomy, external irradiation of the neck
- Drugs - amiodarone, lithium, interferons, interleukin-2, iodide
- Iodine deficiency
- Thyroid infiltration - amyloidosis, tumour
- Congenital hypothyroidism
Other
- Subclinical hypothyroidism
- Nonthyroidal illness (recovery phase)
- Central hyperthyroidism
- TSH receptor defects
- TSH resistance
Interpretation
- Elevated TSH with reduced T4 - consistent with primary hypothyroidism
- Elevated TSH with normal T4 - suggestive of subclinical hypothyroidism
- Elevated TSH with elevated T4 - suggestive of central hyperthyroidism
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