Addison Disease

A medical condition in which the adrenal glands do not produce enough cortisol or, in some cases, aldosterone, causing such problems as weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkened patches of skin. It occurs somewhat more commonly in people with Type 1 diabetes than in the general population.

Two of the most important hormones made by the adrenal glands, which are located just above each kidney, are cortisol and aldosterone. Cortisol has multiple functions throughout the body, including creating the response to stress; helping to maintain blood pressure and cardiovascular function; slowing the immune system’s inflammatory response; raising blood glucose levels in response to stress or fasting; regulating the metabolism of proteins, carbohydrates, and fats; and maintaining proper arousal and sense of well-being. The amount of cortisol in the body is precisely regulated by the pituitary gland and a region of the brain called the hypothalamus. Aldosterone helps the kidneys retain sodium and excrete potassium, which in turn helps maintain blood pressure as well as balance water and salt in the body.

Most cases of Addison disease, which affects approximately 1 in 100,000 people, are due to gradual destruction of the adrenal cortex, the outer layer of the adrenal gland, by the body’s immune system in a misguided attack. As a result, cortisol levels, and in some cases aldosterone levels, become inadequate. Signs and symptoms of Addison disease, which usually begin gradually, include chronic fatigue that gets worse over time, muscle weakness, loss of appetite, and weight loss. About half of people who have it experience nausea, vomiting, and diarrhea. Other symptoms include orthostatic hypotension (a drop in blood pressure when standing, which can cause dizziness or fainting) and skin changes.

A small fraction of people with Addison disease first seek medical attention because of an “Addisonian crisis,” or acute adrenal insufficiency, which can be life-threatening. Symptoms include sudden, penetrating pain in the lower back, abdomen, or legs; severe vomiting and diarrhea; dehydration; low blood pressure; and loss of consciousness.

Addison disease is treated by replacing the hormones that the adrenal glands are no longer making. A synthetic glucocorticoid called hydrocortisone (brand names Cortef and Hydrocortone) is taken once or twice a day to replace cortisol. If there is a deficiency of aldosterone, a mineralocorticoid called fludrocortisone (Florinef) can be taken twice a day.

People with Type 1 diabetes have a somewhat heightened risk of developing Addison disease. In fact, because of certain genes that confer increased susceptibility to multiple autoimmune diseases, people with Type 1 diabetes and their relatives also have a greater risk of developing Graves disease (in which antibodies stimulate the thyroid gland to produce too much of its hormone, thyroxine), Hashimoto thyroiditis (in which the immune system attacks the thyroid gland, causing it to secrete inadequate thyroid hormone), and pernicious anemia (in which the immune system attacks the parietal cells of the stomach so that they cannot make the protein the body needs to absorb vitamin B12, hindering production of red blood cells). Fortunately, all of these conditions are treatable.