Addison's disease is a rare endocrine or hormonal disorder that occurs when the adrenal glands do not produce enough of the hormone cortisol and in some cases, the hormone aldosterone. The progressive loss of adrenal hormones usually produces a chronic, steadily worsening fatigue, loss of appetite and weight loss, muscle weakness, low blood pressure, nausea and vomiting, and sometimes darkening of the skin in both exposed and non-exposed parts of the body.
Classical Addison's disease results from a loss of both cortisol and aldosterone secretion due to the near total or total destruction of both adrenal glands. This condition is also called primary adrenal insufficiency. If ACTH is deficient, there will not be enough cortisol produced, although aldosterone may remain adequate. This is secondary adrenal insufficiency, which is distinctly different, but similar to Addison's disease, since both include a loss of cortisol secretion.
The slowly progressive chronic symptoms are usually missed or ignored until a sudden event like a flu virus, an accident, or the need for surgery suddenly precipitates a dramatic change for the worse because of the deficient response from the adrenals to one of these stresses. This is referred to as an Addisonian crisis and is a medical emergency.
Addison's disease affects about 1 in 100,000 people. It occurs in all age groups and afflicts men and women equally. A study in London showed thirty-nine cases per million population as of 1960. Twelve were due to tuberculosis. In the non-tuberculosis group, women were three times more likely to have Addison's disease. Extrapolation of these figures to the U.S. would give about 8,800 cases, but this is probably an underestimation.