Adrenal hypofunction



Adrenal hypofunction





Primary adrenal hypofunction or insufficiency (Addison’s disease) originates within the adrenal gland itself and is characterized by decreased mineralocorticoid, glucocorticoid, and androgen secretion. Secondary adrenal hypofunction is due to impaired pituitary secretion of corticotropin and is characterized by decreased glucocorticoid secretion. Secretion of aldosterone, the major mineralocorticoid, is often unaffected.

Addison’s disease is relatively uncommon, though it can occur at any age, in either sex. Secondary adrenal hypofunction occurs when a patient abruptly stops taking an exogenous steroid after long-term therapy or when the pituitary is injured by a tumor or by infiltrative or autoimmune processes. With an early diagnosis and adequate replacement therapy, the prognosis for the person with adrenal hypofunction is good.

Adrenal crisis (addisonian crisis), a critical deficiency of mineralocorticoids and glucocorticoids, generally follows acute stress, sepsis, trauma, surgery, or omission of steroid therapy in patients who have chronic adrenal insufficiency. A medical emergency, adrenal crisis necessitates immediate, vigorous treatment.


Causes

The following are causes of primary and secondary adrenal hypofunction and adrenal crisis.


Primary hypofunction

Addison’s disease occurs when more than 90% of both adrenal glands are destroyed. Such destruction usually results from an autoimmune process (autoimmune
adrenalitis) in which circulating antibodies react specifically against the adrenal tissue.


Other causes include tuberculosis (once the chief cause; now responsible for less than 10% of adult cases), bilateral adrenalectomy, hemorrhage into the adrenal gland, neoplasms, and infections (histoplasmosis, cytomegalovirus). Rarely, a family history of autoimmune disease predisposes the patient to Addison’s disease and other endocrinopathies.


Secondary hypofunction

Secondary hypofunction, which results in glucocorticoid deficiency, can stem from hypopituitarism (causing decreased corticotropin secretion), abrupt withdrawal of long-term corticosteroid therapy (long-term exogenous corticosteroid stimulation suppresses pituitary corticotropin secretion and results in adrenal gland atrophy), or the removal of a corticotropin-secreting tumor.


Adrenal crisis

After trauma, surgery, or other physiologic stress, adrenal crisis exhausts the body’s stores of glucocorticoids in a person with adrenal hypofunction.


Signs and symptoms

Signs and symptoms vary with the type of adrenal hypofunction.


Primary hypofunction

Addison’s disease typically produces weakness, fatigue, weight loss, nausea, vomiting, and anorexia. Asthenia (constant fatigue) is the cardinal symptom, most evident in times of stress.

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Jun 16, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Adrenal hypofunction
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