Addison’s disease is a severe or total deficiency of the hormones made in the adrenal cortex, caused by its destruction. The adrenal glands are triangular in shape, roughly up to three inches (7.6 cm) by one inch (2.5 cm) in size, and one gland sits on the top of each kidney. The outer part of the adrenal gland (called the cortex) makes three separate types of hormone:
- Glucocorticoids (especially cortisol)
- Mineralocorticoids (especially aldosterone)
- Sex steroids (or androgens).
Addison’s disease is named after Thomas Addison, the British physician who first described the condition in on the Constitutional and Local Effects of Disease of the Suprarenal Capsules (1855). All of Addison’s six original patients had tuberculosis of the adrenal glands. While Addison’s six patients in 1855 all had adrenal tuberculosis, the term “Addison’s disease” does not imply an underlying disease process.
The condition was initially considered a form of anemia associated with the adrenal glands. Because little was known at the time about the adrenal glands (then called “Supra-Renal Capsules”), Addison’s monograph describing the condition was an isolated insight. As the adrenal function became better known, Addison’s monograph became known as an important medical contribution and a classic example of careful medical observation.
Epidemiology of Addison’s disease
Addison’s disease affects males and females in equal numbers. Approximately 1 in 100,000 people in United States have Addison’s disease. The overall prevalence is estimated to be between 40 and 60 people per million of the general population. Because cases of Addison’s disease may go undiagnosed, it is difficult to determine its true frequency in the general population. Addison’s disease can potentially affect individuals of any age, but usually occurs in individuals between 30-50 years of age.
- Injury of adrenal gland
- Autoimmune Disease
- Steroid Therapy
- Tuberculosis of adrenal glands
- Operation on adrenal gland
- Amyloid Disease
- Use of certain medications
- Genetic Predisposition to Disease
- Primary Hypercoagulable State
- By far the most common cause of Addison’s disease is autoimmunity. This is known as autoimmune Addison’s disease. Normally the body’s immune system attacks invading viruses and bacteria to defend the body. In cases of autoimmunity, the immune system makes a mistake, attacking and destroying the adrenal cortex as if it was an infection.
- Rare causes of Addison’s disease include infections such as tuberculosis, removal of the adrenal glands by surgery, bleeding into the adrenal glands (for instance after abdominal injuries), cancer of the adrenal glands and genetic defects such as adrenoleukodystrophy.
- The pituitary gland produces hormones that affect the adrenal gland. If the pituitary gland stops working properly, this can cause secondary adrenal insufficiency.
Addison’s disease symptoms usually develop slowly, often over several months, and may include:
- Extreme fatigue
- Weight loss and decreased appetite
- Darkening of your skin (hyperpigmentation)
- Low blood pressure, even fainting
- Salt craving
- Low blood sugar (hypoglycemia)
- Nausea, diarrhea or vomiting
- Abdominal pain
- Muscle or joint pains
- Body hair loss or sexual dysfunction in women
- Low Blood Pressure
- Decreased vascular resistance
Diagnosis and test
If your doctor thinks that you may have Addison’s disease, you may undergo some of the following tests:
Blood test: Measuring your blood levels of sodium, potassium, cortisol and ACTH gives your doctor an initial indication of whether adrenal insufficiency may be causing your signs and symptoms. A blood test can also measure antibodies associated with autoimmune Addison’s disease.
ACTH stimulation test: This test involves measuring the level of cortisol in your blood before and after an injection of synthetic ACTH. ACTH signals your adrenal glands to produce cortisol. If your adrenal glands are damaged, the ACTH stimulation test shows that your output of cortisol in response to synthetic ACTH is limited or nonexistent.
Insulin-induced hypoglycemia test: Occasionally, doctors suggest this test if pituitary disease is a possible cause of adrenal insufficiency (secondary adrenal insufficiency). The test involves checking your blood sugar (blood glucose) and cortisol levels at various intervals after an injection of insulin. In healthy people, glucose levels fall and cortisol levels increase.
Imaging tests: Your doctor may have you undergo a computerized tomography (CT) scan of your abdomen to check the size of your adrenal glands and look for other abnormalities that may give insight to the cause of the adrenal insufficiency. Your doctor may also suggest an MRI scan of your pituitary gland if testing indicates you might have secondary adrenal insufficiency.
Treatment and medications
- Your treatment will depend on what is causing your condition. Your doctor may prescribe medications that regulate the adrenal gland.
- Following the treatment plan that your doctor creates for you is very important. Untreated Addison’s disease can lead to an Addisonian crisis.
- If your condition has gone untreated for too long, and has progressed to a life-threatening condition called Addisonian crisis, your physician may prescribe medication to treat that first. Addisonian crisis causes low blood pressure, high potassium in the blood, and low blood sugar levels.
- You may need to take a combination of glucocorticoids medications (drugs that stop inflammation) to improve your health. These medications will be taken for the rest of your life and you cannot miss a dose.
- Hormone replacements may be prescribed to replace hormones that your adrenal glands are not making.
Prevention of Addison’s disease is more focused on relieving symptoms and preventing an Addisonian crisis that is triggered in highly stressful environments. Preventing this disorder may include treating underlying conditions and limiting risk factors such as autoimmune diseases.
The following risk factors may prevent Addison’s disease include:
- Treating fungal infections.
- Controlling diabetes.
- Identify cancer symptoms to prevent spread of cells into adrenal glands and bloodstream.
- Treating bacterial infection such as tuberculosis
For those who live with Addison’s disease, reducing stress and engaging in relaxing activities may prevent severe symptoms and complications.