The adrenal glands are small, paired endocrine organs located on the upper end of each kidney. The principal hormones produced by the adrenals include adrenalin, aldosterone and cortisol. Male sex hormones, or androgens, are also produced in small amounts. Abnormal hormone levels associated with diseases of the adrenal glands have wide-ranging effects on the human body. Signs, symptoms and blood tests to measure hormone levels aid in the diagnosis of adrenal gland diseases.
Addison's Disease
Addison's disease, or primary adrenal insufficiency, is a condition of inadequate production of adrenal hormones, principally cortisol and aldosterone. An errant immune system attack on the adrenals with subsequent tissue destruction is responsible for approximately 80 percent of cases of Addison's disease, reports the National Institute of Diabetes and Digestive and Kidney Diseases. Other possible causes of adrenal damage leading to primary adrenal insufficiency include tuberculosis and other adrenal infections, amyloidosis, adrenal hemorrhage and cancerous invasion of the glands.
Signs and symptoms of Addison's disease include decreased appetite and weight loss, chronic fatigue, increased skin pigmentation, low blood pressure, dizziness on standing, depression, headaches, nausea and vomiting, diarrhea, salt cravings and low blood sugar. Women commonly experience menstrual irregularities. Treatment for Addison's disease involves replacement of deficient aldosterone and cortisol.
Secondary Adrenal Insufficiency
The pituitary gland of the brain stimulates adrenal production of cortisol through the release of adrenocorticotropin, or ACTH. Insufficient pituitary stimulation of the adrenal glands caused by abnormally low ACTH release leads to deficient cortisol production. This condition is termed secondary adrenal insufficiency.
The Merck Manual for Healthcare Professionals reports that possible causes of secondary adrenal insufficiency include pituitary gland tumors, head trauma that damages the pituitary, and prolonged treatment with corticosteroids medications such as dexamethasone, prednisone, prednisolone and hydrocortisone. Signs and symptoms of secondary adrenal insufficiency mirror those of Addison's disease, with the exception of increased skin pigmentation, which does not occur with this disorder. Treatment of secondary adrenal insufficiency involves replacement of insufficient cortisol with oral glucocorticoid medication.
Primary Aldosteronism
Primary aldosteronism denotes a condition wherein the adrenal glands independently overproduce the hormone aldosterone. Increased aldosterone production may arise due to adrenal tissue overgrowth or a tumor of the adrenal cortex--the outer region of the adrenal gland. Inherited adrenal disorders are an uncommon cause of primary aldosteronism.
The Mayo Clinic explains that aldosterone stimulates water and salt retention by the kidneys. The elevated aldosterone concentration present with primary aldosteronism causes increased blood pressure, an abnormally low blood potassium and intermittent weakness. High blood pressure associated with aldosteronism proves notorious difficult to control with medications. Poor response to medication often triggers testing for aldosteronism as the underlying cause of high blood pressure.
Surgical removal of adrenal tumors is the definitive treatment for primary aldosteronism caused by these lesions. Medication to block the effects of aldosterone is the primary treatment for adrenal overgrowth, or hyperplasia, reports The Merck Manual for Healthcare Professionals.
References
- National Institute of Diabetes and Digestive and Kidney Diseases: Adrenal Insufficiency and Addison's Disease
- Merck Manual for Healthcare Professionals: Addison's Disease
- Merck Manual for Healthcare Professionals: Secondary Adrenal Insufficiency
- MayoClinic.com: Primary Aldosteronism
- Merck Manual for Healthcare Professionals: Primary Aldosteronism (Conn's Syndrome)
