Central hypothyroidism

Central hypothyroidism refers to hypothyroidism caused by either a pituitary disorder (secondary hypothyroidism) or a hypothalamic disorder (tertiary hypothyroidism).

If a patient has a low serum free thyroxine (T₄) concentration and clinical features of hypothyroidism, but no elevation in serum thyroid stimulating hormone (TSH) concentration (ie low or ‘inappropriately normal’ TSH), assess the patient for hypopituitarism. See Chronic hypopituitarism and Thyroid hormone replacement in hypopituitarism for more information.

A low serum T₄ concentration with a low or normal serum TSH concentration can also indicate a hypothalamic disorder.