Addison's disease is a severe or total deficiency of the hormones made in the adrenal cortex, caused by a destruction of the adrenal cortex. There are normally two adrenal glands, located above each kidney. The adrenal glands are really two endocrine ( ductless or hormone producing ) glands in one. The inner part of the adrenal ( called the medulla ) produces epinephrine ( also called adrenaline ) which is produced at times of stress and helps the body respond to "fight or flight" situations by raising the pulse rate, adjusting blood flow, and raising blood sugar. However, the absence of the adrenal medulla and epinephrine does not cause disease.

Addison's disease is a rare endocrine, or hormonal disorder that affects about 1 in 100,000 people. It occurs in all age groups and afflicts men and women equally. The disease is characterized by weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and nonexposed parts of the body.

What causes Addison's Disease?

Failure to produce adequate levels of cortisol, or adrenal insufficiency, can occur for different reasons. The problem may be due to a disorder of the adrenal glands themselves (primary adrenal insufficiency) or to inadequate secretion of ACTH by the pituitary gland (secondary adrenal insufficiency).

How is Addison's disease treated?

Treatment of Addison's disease involves replacing, or substituting, the hormones that the adrenal glands are not making. Cortisol is replaced orally with hydrocortisone tablets, a synthetic glucocorticoid, taken once or twice a day. If aldosterone is also deficient, it is replaced with oral doses of a mineralocorticoid called fludrocortisone acetate (Florinef), which is taken once a day. Patients receiving aldosterone replacement therapy are usually advised by a doctor to increase their salt intake. Because patients with secondary adrenal insufficiency normally maintain aldosterone production, they do not require aldosterone replacement therapy. The doses of each of these medications are adjusted to meet the needs of individual patients.

During an addisonian crisis, low blood pressure, low blood glucose, and high levels of potassium can be life threatening. Standard therapy involves intravenous injections of hydrocortisone, saline (salt water), and dextrose (sugar). This treatment usually brings rapid improvement. When the patient can take fluids and medications by mouth, the amount of hydrocortisone is decreased until a maintenance dose is achieved. If aldosterone is deficient, maintenance therapy also includes oral doses of fludrocortisone acetate.

Proper maintenance treatment requires regular visits to a physician for examinations, laboratory tests, and discussions about symptoms. Certain blood tests, including sodium, potassium, blood counts and plasma renin are very useful in monitoring the response to adjustments in dosage. There is no single blood or urine test that is perfect by itself.