Topic Overview
What is Addison's disease?
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.
What causes Addison's disease?
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.
What are the symptoms?
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.2 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.
How is Addison's disease diagnosed?
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.
How is it treated?
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.
Frequently Asked
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