TSH determination

Last reviewed 07/2021

High levels of free thyroid hormones in combination with low levels of TSH indicates hyperthyroidism due to autonomous activity of the thyroid.

A high TSH excludes hyperthyroidism except in the very rare situations of:

  • TSH-producing pituitary tumours
  • thyroid hormone resistance

Low serum TSH concentrations may be seen in some patients with non-thyroidal illnesses and in those prescribed certain drugs e.g. dopamine, glucocorticoids (1).

Ref: Prescribers' Journal (1999), 39 (1), 1-8.