Addison's disease results when your adrenal glands are damaged, producing insufficient amounts of the hormone cortisol and often aldosterone as well. These glands are located just above your kidneys. As part of your endocrine system, they produce hormones that give instructions to virtually every organ and tissue in your body.
Your adrenal glands are composed of two sections. The interior (medulla) produces adrenaline-like hormones. The outer layer (cortex) produces a group of hormones called corticosteroids, which include glucocorticoids, mineralocorticoids and male sex hormones (androgens).
Some of the hormones the cortex produces are essential for life â the glucocorticoids and the mineralocorticoids.
- Glucocorticoids. These hormones, which include cortisol, influence your body's ability to convert food fuels into energy, play a role in your immune system's inflammatory response and help your body respond to stress.
- Mineralocorticoids. These hormones, which include aldosterone, maintain your body's balance of sodium and potassium to keep your blood pressure normal.
- Androgens. These male sex hormones are produced in small amounts by the adrenal glands in both men and women. They cause sexual development in men, and influence muscle mass, libido and a sense of well-being in both men and women.
Primary adrenal insufficiency
Addison's disease occurs when the cortex is damaged and doesn't produce its hormones in adequate quantities. Doctors refer to the condition involving damage to the adrenal glands as primary adrenal insufficiency.
The failure of your adrenal glands to produce adrenocortical hormones is most commonly the result of the body attacking itself (autoimmune disease). For unknown reasons, your immune system views the adrenal cortex as foreign, something to attack and destroy.
Other causes of adrenal gland failure may include:
- Other infections of the adrenal glands
- Spread of cancer to the adrenal glands
- Bleeding into the adrenal glands, which may present as adrenal crisis without any preceding symptoms.
Secondary adrenal insufficiency
Adrenal insufficiency can also occur if your pituitary gland is diseased. The pituitary gland makes a hormone called adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to produce its hormones. Inadequate production of ACTH can lead to insufficient production of hormones normally produced by your adrenal glands, even though your adrenal glands aren't damaged. Doctors call this condition secondary adrenal insufficiency.
Another more common cause of secondary adrenal insufficiency occurs when people who take corticosteroids for treatment of chronic conditions, such as asthma or arthritis, abruptly stop taking the corticosteroids.
If you have untreated Addison's disease, an addisonian crisis may be provoked by physical stress, such as an injury, infection or illness.