Addison's disease, also known as chronic adrenal insufficiency, is a condition in which the adrenal glands do not produce enough hormones. These hormones include cortisol, corticosterone, aldosterone and some steroids. Aldosterone, cortisol and corticosterone play a role in regulating water balance, acid-base balance, and sodium and potassium homeostasis. The National Endocrine and Metabolic Diseases Information Service reports that the incidence of Addison's disease is between 1 and 4 for every 100,000 people.
Addisonian Crisis
Because the destruction of the adrenal gland cortex is often gradual and the symptoms are mild, Addison's disease often goes undiagnosed until a sudden illness or accident worsens the condition. The worsening of symptoms is called Addisonian crisis, or acute adrenal insufficiency, and can be life-threatening. The occurrence of electrolyte imbalances and increased blood acidity aid in the diagnosis of Addison's disease, but an accurate diagnosis also requires the measurement of blood levels of cortisol and aldosterone before and after administration of adrenocorticotropic hormone. These tests are performed after a person in Addisonian crisis has been stabilized.
Hyponatremia
Aldosterone is a hormone secreted by the adrenal glands that regulates the reabsorption of water from urine. If its levels are deficient, more water and sodium will be excreted. Low blood levels of sodium, or hyponatremia, often cause a person with Addison's disease to crave salty foods.
Hyperkalemia
Aldosterone has the opposite effect on potassium because potassium ions are exchanged for every excreted sodium ion. Therefore, aldosterone deficiency can result in elevated blood levels of potassium, also called hyperkalemia.
Metabolic Acidosis
Metabolic acidosis, or the accumulation of acid in the blood, is less commonly observed in patients with Addison's disease. It is also caused by aldosterone deficiency. An article in the "Postgraduate Medical Journal" does note that metabolic acidosis is sometimes apparent in patients experiencing an Addisonian crisis.
Hypercalcemia
High levels of blood calcium, or hypercalcemia, are also not a common occurrence in patients with Addison's disease, but the article in "Postgraduate Medical Journal" reports that it may be present during Addisonian crisis.
Treatment
To correct the electrolyte imbalances, low blood volume and acidosis patients having an Addisonian crisis are treated by intravenous administration of fluids and sodium. The National Endocrine and Metabolic Diseases Information Service says the treatment for Addison's disease is hormone replacement. Cortisol and corticosterone are replaced with a synthetic glucocorticoid such as hydrocortisone or dexamethasone and if aldosterone is also deficient, the mineralocorticoid fludrocortisone acetate is recommended.
