hormonal and metabolic disorders
Overview of the Pituitary Gland
Pituitary gland malfunction
The pituitary gland can malfunction in several ways, usually as a result of developing a noncancerous tumor (adenoma). The tumor may overproduce one or more pituitary hormones, or the tumor may press on the normal pituitary cells, causing underproduction of one or more pituitary hormones. The tumor may also cause Enlargement of the Pituitary Gland , with or without disturbing hormone production. Sometimes there is overproduction of one hormone by a pituitary tumor and underproduction of another at the same time due to pressure. Sometimes excess cerebrospinal fluid can fill the space around the pituitary gland and compress it ( Empty Sella Syndrome ). The pressure may cause the pituitary to overproduce or underproduce hormones. Too little or too much of a pituitary hormone results in a wide variety of symptoms. Overproduction of pituitary hormonescauses disorders, including Gigantism and Acromegaly : Growth hormone Cushing Syndrome : Adrenocorticotropic hormone ( Prolactinoma (the secretion of breast milk by men or by women when not pregnant): Prolactin Erectile Dysfunction (ED) : Prolactin Overview of Infertility (particularly in women): Prolactin Underproduction of pituitary hormonescauses disorders, including deficiency ( ArginineVasopressin Deficiency (Central Diabetes Insipidus) ): Hypopituitarism : Multiple hormones Doctors can diagnose pituitary gland malfunction using several tests. Imaging tests, most commonly magnetic resonance imaging (MRI), can show whether the pituitary has enlarged (for example, if a Enlargement of the Pituitary Gland is present) or shrunk (for example, in Doctors can measure the levels of pituitary hormones, usually by a simple blood test. Doctors select which pituitary hormone levels they want to measure depending on the person's symptoms. Sometimes, levels of pituitary hormones are not easy to interpret because the levels vary greatly during the day and according to the body's needs. For these hormones, measuring a random blood sample does not provide useful information. For some of those hormones, doctors give a substance that would normally affect hormone production and then they measure the level of the hormone. For example, if a doctor injectsinsulin, the levels ofACTH, growth hormone, and prolactin should increase. Rather than measuring growth hormone levels directly, doctors often measure another hormone,insulin-like growth factor 1 (IGF-1). Growth hormone is produced in bursts and its levels quickly fall, but IGF-1 levels reflect the overall daily production of growth hormone. For all of these reasons, interpreting the results of blood tests for pituitary hormones is complex. 