This document discusses hyperpituitarism and hypopituitarism, which are conditions related to increased or decreased secretion of hormones by the pituitary gland. Hyperpituitarism involves increased secretion of growth hormone and antidiuretic hormone, which can cause acromegaly or gigantism from excess growth hormone, or syndrome of inappropriate antidiuretic hormone secretion from excess antidiuretic hormone. Hypopituitarism involves decreased secretion of pituitary hormones and can be caused by tumors, congenital defects, or pituitary surgery. It can affect growth, puberty, thyroid function, stress response, and other areas depending on which hormones are deficient.