From Wikipedia, the free encyclopedia - View original article
|Classification and external resources|
|Classification and external resources|
Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones, primarily cortisol; but may also include impaired production of aldosterone (a mineralocorticoid), which regulates sodium conservation, potassium secretion, and water retention. Craving for salt or salty foods due to the urinary losses of sodium is common.
Addison's disease and congenital adrenal hyperplasia can manifest as adrenal insufficiency. If not treated, adrenal insufficiency may result in severe abdominal pains, vomiting, profound muscle weakness and fatigue, depression, extremely low blood pressure (hypotension), weight loss, kidney failure, changes in mood and personality, and shock (adrenal crisis). An adrenal crisis often occurs if the body is subjected to stress, such as an accident, injury, surgery, or severe infection; death may quickly follow.
Adrenal insufficiency can also occur when the hypothalamus or the pituitary gland does not make adequate amounts of the hormones that assist in regulating adrenal function. This is called secondary or tertiary adrenal insufficiency and is caused by lack of production of ACTH in the pituitary or lack of CRH in the hypothalamus, respectively.
There are three major types of adrenal insufficiency.
Symptoms include: hypoglycemia, dehydration, weight loss, and disorientation. Symptoms may also include weakness, tiredness, dizziness, low blood pressure that falls further when standing (orthostatic hypotension), cardiovascular collapse, muscle aches, nausea, vomiting, and diarrhea. These problems may develop gradually and insidiously. Addison's disease can present with tanning of the skin that may be patchy or even all over the body. Characteristic sites of tanning are skin creases (e.g. of the hands) and the inside of the cheek (buccal mucosa). Goitre and vitiligo may also be present.
Causes of acute adrenal insufficiency are mainly Waterhouse-Friderichsen syndrome, sudden withdrawal of long-term corticosteroid therapy, and stress in patients with underlying chronic adrenal insufficiency. The latter is termed critical illness–related corticosteroid insufficiency.
For chronic adrenal insufficiency, the major contributors are autoimmune adrenalitis, tuberculosis, AIDS, and metastatic disease. Minor causes of chronic adrenal insufficiency are systemic amyloidosis, fungal infections, hemochromatosis, and sarcoidosis.
Autoimmune adrenalitis may be part of Type 2 autoimmune polyglandular syndrome, which can include type 1 diabetes, hyperthyroidism, and autoimmune thyroid disease (also known as autoimmune thyroiditis, Hashimoto's thyroiditis, and Hashimoto's disease). Hypogonadism and pernicious anemia may also present with this syndrome.
Adrenal insufficiency can also result when a patient has a craniopharyngioma, which is a histologically benign tumor that can damage the pituitary gland and so cause the adrenal glands not to function. This would be an example of secondary adrenal insufficiency syndrome.
Adrenal insufficiency can also occur when a patients suffers from Chronic Fatigue Syndrome long term. This can induce Adrenal Insufficiency through oxidative damage to any of the Hypothalamic–pituitary–adrenal axis (HPA-Axis) organs: the Hypothalamus, the Pituitary gland or the Adrenal gland. Onset in these cases is often insidious.
If the person is in adrenal crisis, the ACTH stimulation test may be given. If not in crisis, cortisol, ACTH, aldosterone, renin, potassium, and sodium are tested from a blood sample before the decision is made whether the ACTH stimulation test needs to be performed. X-rays or CT of the adrenals may also be done. The best test for adrenal insufficiency of autoimmune origin, representing more than ninety percent of all cases in a Western population, is measurement of 21-hydroxylase autoantibodies.
|Source of pathology||CRH||ACTH||DHEA||DHEA-S||cortisol||aldosterone||renin||Na||K||Causes5|
|low||low||low||low||low3||low||low||low||low||tumor of the hypothalamus (adenoma), antibodies, environment (i.e. toxins), head injury|
|high2||low||low||low||low3||low||low||low||low||tumor of the pituitary (adenoma), antibodies, environment, head injury,|
surgical removal6, Sheehan's syndrome
|high||high||high||high||low4||low||high||low||high||tumor of the adrenal (adenoma), stress, antibodies, environment, Addison's Disease, trauma, surgical removal (resection), miliary tuberculosis of the adrenal|
|1||Automatically includes diagnosis of secondary (hypopituitarism)|
|2||Only if CRH production in the hypothalamus is intact|
|3||Value doubles or more in stimulation|
|4||Value less than doubles in stimulation|
|5||Most common, does not include all possible causes|
|6||Usually because of very large tumor (macroadenoma)|
|7||Includes Addison's disease|
"Results of ACTH and cortisol tests are often evaluated together. The table below indicates the common patterns of ACTH and cortisol seen with different diseases involving the adrenal and pituitary glands.
|Cushing disease (pituitary tumor producing ACTH)||High||High|
|"Ectopic" ACTH (ACTH made by a tumor outside the pituitary, usually in the lung)||High||High|
|Addison disease (underactive or damaged adrenal glands)||Low||High|
An increased ACTH result can mean that a person has Cushing disease, Addison disease, or ectopic ACTH-producing tumors. A decreased ACTH result can be due to an adrenal tumor, steroid medication, or hypopituitarism." 
(To balance sodium, potassium and increase water retention)