CausesBy Mayo Clinic staff
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|Pituitary gland and hypothalamus|
Although many problems can lead to low pituitary function, Sheehan's syndrome is caused by severe blood loss during or after childbirth. Blood loss at that time can be particularly damaging to the pituitary gland, destroying hormone-producing tissue so that the gland can't function normally.
Experts aren't sure why this is the case. One theory is that since the pituitary gland enlarges during pregnancy, it's more prone to damage. The severe drop in blood pressure (hypotension) that occurs during hemorrhage also could damage the pituitary.
Pituitary hormones regulate the rest of your endocrine system, signaling other glands to increase or decrease production of the hormones that control metabolism, fertility, wound healing and many other vital processes. A lack of any of these hormones can cause problems throughout your body — although signs and symptoms may develop so gradually that they escape notice.
Hormones that your pituitary secretes include:
- Growth hormone (GH). This hormone controls bone and tissue growth and maintains the appropriate balance of muscle and fat tissue.
- Anti-diuretic hormone (ADH). By regulating urine production, this hormone manages water balance in your body. A deficiency of ADH results in excess urination and thirst, a condition called diabetes insipidus.
- Thyroid-stimulating hormone (TSH). This hormone stimulates your thyroid gland to produce key hormones that regulate your metabolism. Shortage of TSH results in an underactive thyroid gland (hypothyroidism).
- Luteinizing hormone (LH). In men, LH regulates testosterone production. In women, it fosters production of estrogen.
- Follicle-stimulating hormone (FSH). Working in tandem with LH, FSH helps stimulate sperm production in men, and egg development and ovulation in women.
- Adrenocorticotropic hormone (ACTH). This hormone stimulates your adrenal glands to produce cortisol and other hormones. Cortisol helps your body deal with stress and influences many body functions, including blood pressure, heart function and your immune system. A low level of adrenal hormones caused by pituitary damage is called secondary adrenal insufficiency.
- Prolactin. This hormone regulates the development of female breasts, as well as the production of breast milk.
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- Nieman LK. Clinical manifestations of adrenal insufficiency in adults. http://www.uptodate.com/home/index.html. Accessed Nov. 15, 2010.
- Montoro MN. Thyroid and other endocrine disorders during pregnancy. In: DeCherney AH, et al. Current Diagnosis & Treatment Obstetrics & Gynecology. 10th ed. New York, N.Y.: McGraw-Hill; 2007. http://www.accessmedicine.com/content.aspx?aID=2387051. Accessed Nov. 13, 2010.
- Generalized hypopituitarism. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec12/ch151/ch151c.html. Accessed Nov. 16, 2010.
- Pituitary disorders overview. The Hormone Foundation. http://www.hormone.org/Pituitary/overview.cfm. Accessed Nov. 16, 2010.
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