Addison's Disease (primary adrenocortical insufficiency) is a rare condition that develops when the adrenal glands, located above the kidneys, are not able to produce enough of the hormones cortisol and, less commonly, aldosterone.
Cortisol affects almost every organ in the body and is important for normal body function. The adrenal glands release cortisol to help the body cope with stress from illness, injury, surgery, childbirth, or other reasons. Aldosterone helps the body retain salt and maintain blood pressure.
Cortisol production by the adrenal glands is controlled by the brain's hypothalamus and in the pituitary gland below the brain. The hypothalamus signals the pituitary gland to produce adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal glands to produce cortisol. If the adrenal glands cannot produce enough cortisol, the condition is called primary adrenocortical insufficiency (hypocortisolism), or Addison's disease. When the hypothalamus or the pituitary gland is not working correctly to produce enough ACTH, the condition is called secondary adrenocortical insufficiency. This topic focuses on primary adrenocortical insufficiency.
Addison's Disease usually develops when the body's immune system destroys the part of the adrenal glands that produces cortisol and aldosterone. Addison's Disease also can develop when the adrenal glands are destroyed by:
- Cancer that has spread to the adrenal glands. This is most commonly seen in lung cancer.
- Bleeding into the adrenal glands as a side effect of blood-thinning medicine.
- Infections, such as tuberculosis, HIV, or certain bacterial infections, such as meningococcemia (caused by meningococcal bacteria in the bloodstream).
- Some types of surgery or radiation treatments.
- Injury to the adrenal glands during the late stages of pregnancy or during the delivery of the baby. This is rare.
- Using certain medicines, such as high doses of ketoconazole.
Addison's Disease can affect people at any age, including children. Addison's Disease caused by the immune system destroying the adrenal gland is more frequent in women than in men, but when caused by tuberculosis, it is more frequent in men.1 It can also develop if someone takes a cortisol-like medicine, such as prednisone, for a long period of time then suddenly stops the treatment.
The most common symptoms of Addison's Disease are fatigue, weakness, and unexpected weight loss. Your skin color also may become darker, a condition called hyperpigmentation. Other possible symptoms include lightheadedness; loss of appetite; nausea, vomiting, and diarrhea; and a craving for salt. In people with diabetes mellitus, episodes of low blood sugar (hypoglycemia) often become more frequent and more severe.
Symptoms usually develop slowly and often are not obvious until an adrenal crisis (Addisonian crisis) occurs because of a stressful event, such as a severe infection, trauma, surgery, or dehydration. The body is not able to produce enough cortisol to cope with stress. If not treated, an adrenal crisis may be fatal because of shock from a steep drop in blood pressure.
In a few cases, Addison's Disease develops rapidly. These people may already be in an adrenal crisis when they see a doctor. Symptoms of an adrenal crisis can include vomiting and diarrhea; weakness and lightheadedness; restlessness, confusion, or feeling fearful; difficulty staying awake; and a high fever.
Addison's Disease is diagnosed by taking your medical history, a physical examination, and laboratory tests. During the medical history, your doctor will ask about your symptoms, whether you have a family history of the condition, and whether you have had cancer, tuberculosis, or HIV infection. During the physical examination, your doctor will check for hyperpigmentation, low blood pressure, and dehydration.
Laboratory tests can show whether you have high potassium and low sodium levels in your blood—signs of possible Addison's disease. If your doctor suspects you have Addison's Disease, he or she will check your blood cortisol and ACTH levels. If your ACTH level is very high, and your cortisol level is low, that may be enough to diagnose Addison's Disease.
If the diagnosis is still not clear, an ACTH stimulation test may be done. You will be given a man-made form of ACTH to see whether your body creates cortisol. A low level of cortisol after an injection of ACTH indicates adrenal insufficiency. Further tests will show whether you have primary adrenocortical insufficiency (Addison's Disease) or a related condition called secondary adrenocortical insufficiency. Your doctor may recommend imaging tests of the adrenal glands, the pituitary gland, or the hypothalamus, after the problem area is found.
Your doctor may start treatment during the testing if he or she thinks adrenocortical insufficiency is likely. If treatment is found to be unnecessary, it can be stopped after testing is complete.
If you have Addison's Disease (or adrenal failure from another cause), you need to take medicine for the rest of your life to replace the cortisol and aldosterone your body no longer produces. You may be given hydrocortisone, because it can function like both of these hormones. If you receive another steroid to replace cortisol, you also may take a medicine (usually fludrocortisone) to replace aldosterone. The dose of medicine may need to be increased during times of stress or illness. In addition, you may need to add extra salt to food during hot and humid weather to replace salt lost through sweating.
Any person with Addison's Disease should always wear medical identification (such as a medical alert bracelet or necklace). If you are injured or ill and cannot tell medical personnel you have Addison's Disease, low levels of cortisol could lead to death.
You can lead a long, healthy life by following treatment and preventing an adrenal crisis.
This infomation was taken from the University of Michigan Health System's Health Library.