The adrenal glands, small triangular shaped glands, reside on top of each kidney. These glands consist of the outer region known as the adrenal cortex and the inner core known as the adrenal medulla. The adrenal glands work closely with other glands in the endocrine system, including the hypothalamus and pituitary gland, to produce hormones that help to regulate metabolic functions such as the breakdown and use of sugar, balance the level of water and salts in the body, control stress responses and trigger sexual development. When the adrenal glands fail to work effectively, it results in adrenal gland deficiencies and many bodily functions are affected.
Hormones
Adrenal gland deficiency, a condition known as Addison's disease, occurs when the adrenal glands fail to produce enough of the hormone cortisol, and in some cases the hormone aldosterone. Cortisol helps the body respond to stress by maintaining blood pressure and cardiac function, slowing the inflammatory response, balances the effects of insulin and regulates the metabolism of proteins, carbohydrates and fats. Aldosterone controls the level of salts in the body to maintain blood volume and blood pressure, as described by the University of Maryland Medical Center.
Causes
Primary adrenal gland insufficiency usually occurs when the immune system of the body attacks and destroys the outer layer of the adrenal glands. Approximately 20 percent of adrenal gland deficiency cases occur as a result of tuberculosis, a bacterial infection of the lungs, according to the Pituitary Network Association.
Secondary Adrenal Insufficiency
Secondary adrenal insufficiency describes an adrenal gland deficiency that occurs as a result of a malfunction pituitary gland. The pituitary gland, located at the base of the brain, releases adrenocorticotropin---a hormone that stimulates the adrenal gland. Failure of the pituitary gland to produce adrenocorticotropin causes a decrease in the level of cortisol produced by the adrenal gland.
Symptoms
Because the hormones produced by the adrenal glands affect so many body systems, the symptoms of adrenal gland deficiencies vary. The Merck Manuals Online Medical Library reports the first symptoms to appear as weakness, tiredness and feelings of dizziness when standing. Many patients also develop patches of skin with excessive pigmentation, therefore appearing dark. Addison's disease also causes decreased appetite, weight loss, dehydration, muscle aches, nausea, vomiting, diarrhea and intolerance to cold.
Complications
Symptoms of adrenal gland deficiency usually progress slowly over time. Acute stress, such as that which occurs in an accident, can cause a sudden and severe worsening of symptoms leading to a condition known as Addisonian crisis, according to the National Endocrine and Metabolic Diseases Information Service. Symptoms of this complication include sudden and penetrating pain in the lower back, severe vomiting and diarrhea, dehydration, low blood pressure and loss of consciousness.
