The assessment of pituitary and target organ hormones in the diagnosis of hypopituitarism.
The importance of simultaneous measurements of pituitary and target organ hormone levels should be emphasised. In hypothyroidism, low TSH in conjunction with low thyroxine implies pituitary failure, in contrast to low thyroxine with elevated TSH which implies thyroid failure. Similarly, hypogonadal patients with low testosterone or oestradiol in the presence of (inappropriately) low gonadotrophins, have hypopituitarism.
