Addison's disease—also known as adrenal insufficiency—is rare, so most of us aren't aware of its causes, symptoms, and treatment.

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Addison’s disease—or primary adrenal insufficiency—is caused by damage to the adrenal glands that results in a reduced production of the hormones cortisol, aldosterone, and dehydroepiandrosterone (DHEA). Adrenal insufficiency can lead to a life-threatening adrenal crisis. Fortunately, Addison’s disease is relatively rare. In the developed world, it affects between 20 to 60 people per every million—that’s between 1 in 16,000 and 1 in 50,000. Women are more commonly affected than men.

To understand Addison’s disease, it helps to consider the role of the adrenal glands, endocrine- or hormone-producing organs that sit above each kidney.

As part of the hormonal system, adrenal glands produce cortisol and aldosterone, which are essential for such healthy bodily functions as regulating blood pressure, cellular metabolism, energy production, sodium and potassium balance, and inflammatory and stress responses. They also produce dehydroepiandrosterone (DHEA), which is crucial for the production of the sex hormones androgen and estrogen.

Addison’s Disease Causes and Symptoms

Addison’s disease is caused by disease or damage of the adrenal glands. Primary adrenal insufficiency is rare; more common is secondary adrenal insufficiency. The latter is caused by a lack of adrenocorticotropin (ACTH), a hormone produced by the pituitary gland, in the brain.

What causes Addison’s disease? Most commonly, it arises from autoimmune disorders (such as celiac disease, type 1 diabetes, and Hashimoto thyroiditis) and infections (such as tuberculosis, HIV, and cytomegalovirus).

Rarer causes include adrenal cancer, amyloidosis, surgery, bleeding into the adrenals, genetic defects, and medications. Symptoms begin when at least 90 percent of the adrenal cortex is damaged.

Addison’s disease symptoms can vary and, of course, can overlap with other those of other conditions. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Addison’s disease presents with:

• Adrenal insufficiency
• Chronic, or long-lasting, fatigue
• Muscle weakness
• Loss of appetite
• Weight loss
• Abdominal pain
• Nausea
• Vomiting
• Diarrhea
• Low blood pressure that drops further when a person stands up, causing dizziness or fainting
• Irritability and depression
• Craving salty foods
• Hypoglycemia, or low blood sugar
• Headache
• Sweating
• Irregular or absent menstrual periods
• In women, loss of interest in sex

Adrenal Crisis

Adrenal crisis or Addisonian crisis is a sudden worsening of Addison’s disease usually during surgery, infection, severe injury or pregnancy. Symptoms of adrenal crisis include:

• Sudden, severe pain in the lower back, abdomen, or legs
• Severe vomiting and diarrhea
• Dehydration
• Low blood pressure
• Loss of consciousness

If not treated, an adrenal crisis can cause death.
(Source: NIDDK).

Other complications can come into play, as well. People with Addison’s disease are more susceptible to heart disease, malignancies, and infectious diseases, which in turn lead to an increase in disability and premature death.

Diagnosing Addison’s Disease

• Examination. If your doctor suspects you might have Addison’s disease, he or she will take your medical history and perform a physical examination. You will most likely then be referred to an endocrinologist.
• Basic tests. The next stage is urine and blood tests for cortisol, ACTH and other basic metrics including complete blood count, sodium, potassium, glucose, antibodies and other hormone levels. If your cortisol is low they may order imaging studies of the adrenal (ultrasound) and pituitary glands (CT scan).
• Advanced testing. Other testing may include an ACTH stimulation test or CRH stimulation test. A tuberculin skin test and chest x-ray for TB may be requested if you come from an at-risk area for tuberculosis. An EKG may show characteristic changes due to hyperkalemia (high potassium).

Addison’s Disease Treatment

Treatment options for Addison’s disease can depend on the circumstances:

• Adrenal insufficiency. At this chronic stage, Addison’s disease is treated by with hormone replacement. Cortisol is replaced with a daily dose of a corticosteroid (like prednisolone, hydrocortisone, or dexamethasone). Aldosterone deficiency is treated with fludrocortisone acetate (Florinef). People with Addison’s disease may benefit from dietary advice from a dietitian or nutritionist regarding the sodium, potassium, and calcium content of the food in their diet. Long-term corticosteroid treatment increases the risk of osteoporosis, so calcium and vitamin D supplementation may be needed.