There are different causes for pituitary hypofunction, which all lead to decreased release of pituitary hormones. As a result of this decreased release of pituitary hormones, the endocrine target organs have decreased function. In this picture, three important causes of hypopituitarism are mentioned. (1) A disorder at the level of the hypothalamus (e.g. a tumor): the releasing hormones are not secreted or cannot reach the endocrine cells in the anterior pituitary. (2) A disorder in the vascularisation of the pituitary caused by an infarction

or trauma. (3) A disorder at the level of the endocrine cells of the pituitary mostly as a result of benign tumors. Substitution of all target hormones (thyroxine, glucocorticoids, growth hormone, androgens and estrogens) is necessary, when there is complete hypofunction.
Check out these drugs under their specific headings (hypothalamic-pituitary-thyroid axis, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis).


I. Hypothalamic and pituitary diseases affect either single or multiple hormonal systems. II. Pituitary hormone deficiency is characterised by decreased pituitary hormone levels and increased hormone levels secreted by the target organs.