Addison's disease is a hormonal disorder of the adrenal gland, which is a hormone producing, or endocrine organ, located above the kidneys. The outer shell of the adrenal gland releases stress hormones, sex steroids and mineral regulating hormones. Addison's disease affects the ability of the adrenal gland to make steroids. Consult with a physician for the diagnosis and treatment of medical conditions.
Causes
Damage to the adrenal gland or its ability to synthesize steroids causes Addison's disease. In autoimmune disorders, the immune system mistakenly attacks the adrenal gland, preventing it from releasing hormones into the circulation. Alternatively, cancers of adrenal gland can destroy the tissue, or tumors from other parts of the body can spread to the adrenal glands. Other problems such as infections can damage the ability of the adrenal gland to make hormones. More rare causes include defects at birth with the formation of the glands or genetic disorders that prevent the synthesis of steroids.
Functions
Two of the main hormones produced by the adrenal gland, cortisol and aldosterone, are low and can no longer exert their functions in the body. Cortisol is a stress hormone. It maintains the cardiovascular system, especially by helping keep the blood pressure high. In addition, it keeps the blood sugar levels elevated, regulates metabolism and decreases the inflammatory response. Aldosterone maintains the blood pressure and regulates minerals. It raises levels of sodium and water in the blood and decreases potassium. Addison's disease results in low blood pressure, low blood sugar and sodium with higher potassium.
Diagnosis
The diagnosis of Addison's disease is usually made from a history of worsening fatigue, muscle weakness, loss of appetite, weight loss, GI symptoms such as nausea and vomiting, craving salt, irregular menses in women, headaches, sweating or irritability. Blood tests can confirm the diagnosis. In the ACTH stimulation test, the hormone ACTH is given. Normally, it will raise levels of cortisol; if it does not, then Addison's disease may be confirmed.
Treatment
Salts, fluids and glucose can be given to treat specific problems in mineral, water or sugar balance. Synthetic steroids such as hydrocortisone or dexamethasone are often given to replace cortisol, and fludrocortisone is often given to replace aldosterone. The levels will need to be adjusted regularly to fit the needs of the individual, and certain settings, such as an operation, may require higher doses of medication.
References
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci, et al.; 17th Ed 2008
- "Physiology"; Linda S.Costanzo; 4th Ed 2008
- "Robbins and Cotran Pathologic Basis of Disease"; Vinay Kumar, et al.; 8th Ed 2009
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