Addison's disease is primarily an autoimmune disease whereby the immune system attacks the adrenal glands, which sit on top of the kidneys. As a result of a decrease in the hormones released by the adrenal glands, the kidneys hold onto potassium. A high level of potassium in the bloodstream can lead to fewer reflexes and weak muscles.
Defining Addison's Disease
Addison's disease is the name for the disorder where the adrenal cortex, or the outer part of the adrenal gland, has been destroyed or is no longer functioning. Approximately 80 percent of Americans who have this disease have it as a result of an autoimmune destruction, according to author Paul Fitzgerald, M.D., Clinical Professor of Medicine at the University of California in "Current Medical Diagnosis & Treatment." In an autoimmune disease, rather than attacking foreign substances, the immune system turns on its own organs. For people with Addison's disease, this destruction may take several years.
The Function of the Adrenal Cortex
The adrenal cortex is divided into three sections referred to as zones. The outermost area is the zona glomerulosa, and it is in this area that the aldosterone hormone is made and released. Next is the zona fasciculata, where the cortisol hormone is made and secreted. The third and innermost zone, the zona reticularis, makes and releases the androgen male hormone. Addison's disease primarily causes a drop in aldosterone and cortisol.
Aldosterone, Sodium and Potassium
The cortisol hormone has many functions, including that of raising the amount of glucose in the blood to help people have enough energy to deal with stressful situations. The aldosterone hormone tells the kidneys to reabsorb sodium. This is done when people have lost a great deal of water, as what may happen in profuse sweating, vomiting or diarrhea. Whenever the kidneys hold onto sodium, water will be reabsorbed, but aldosterone also tells the kidneys to secrete potassium.
Addison's Disease and Potassium
Since the adrenal cortex is destroyed in Addison's disease, which results in a low level of cortisol and aldosterone, the kidneys cannot hold onto sodium but instead, they hold onto potassium. The low cortisol and sodium levels can cause low blood pressure, nausea, vomiting and weakness. A high potassium level can interfere with the signals that go from the nerves to the muscles. Thus, people may develop weak muscles and fewer reflexes.
References
- "Current Medical Diagnosis & Treatment 2011"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2011
- "Ganong's Review of Medical Physiology"; Kim Barrett, Ph.D., Susan Barman, Ph.D. et al.; 2010
- The Merck Manual for Healthcare Professionals: Addison's Disease
Member Comments