Addison's disease: Overview of an uncommon but serious condition

Addison's disease is uncommon, thought to affect only about 100 to 140 out of every one million people. But if it's left untreated, this condition that can cause fatigue, weight loss, and muscle weakness, among other serious symptoms. Here's what to know.

What is Addison's disease?

Addison's disease develops when your adrenal glands don't make enough of certain important hormones. These include the stress hormone cortisol, and aldosterone, a hormone that helps regulate your body's sodium and potassium levels — which in turn impact blood volume and blood pressure. Addison's disease is a form of adrenal insufficiency.

Common symptoms of Addison's disease

Addison's disease symptoms usually come on gradually and include:

• marked fatigue
• nausea and vomiting
• abdominal pain
• diarrhea
• loss of appetite
• weight loss
• muscle and joint pain
• muscle spasms
• muscle weakness
• dizziness when you stand up (caused by low blood pressure)
• mood changes
• trouble concentrating
• sudden salt cravings
• loss of body hair
• irregular menstrual periods
• decreased libido.

Hyperpigmentation, the appearance of dark patches on the skin, is often an early sign of Addison's disease.

Symptoms of Addison's disease can be vague and develop slowly, so it's easy to miss them. Let your doctor know if you always feel tired or weak, or if you've lost weight without trying to.

What causes Addison's disease?

Addison's disease is caused by damage to the adrenal glands — small glands that sit on the kidneys and produce a variety of hormones that regulate everything from metabolism and blood pressure to immune functioning. Up to 90% of the time, this damage is a result of an autoimmune disease in which the body's own immune system attacks the adrenal glands.

Certain infections, such as tuberculosis, can also damage your adrenal glands.

Rarely, Addison's disease can be caused by a genetic disorder, or by adrenal cancer. Certain medicines like antifungal medicines can also trigger the condition.

Who is at increased risk for Addison's disease?

Anyone can develop Addison's disease. But it's more frequently seen in women, and in people between the ages of 30 and 50. You may also be at increased risk if you have another autoimmune condition, such as Type 1 diabetes, Graves' disease, or pernicious anemia.

How is Addison's disease diagnosed?

There are several steps involved in an Addison's disease diagnosis. Your doctor will first examine you and ask you questions about your health, as well as your medical history. They will then check your blood cortisol levels. If levels of this essential hormone that is produced by the adrenal glands are low, they will run the following tests:

ACTH blood level. Normally, the pituitary gland in your brain releases a protein called adrenocortical hormone (ACTH) into your bloodstream to stimulate your adrenal glands to make cortisol. If your blood level of ACTH is low, then the problem is in your pituitary gland. If ACTH blood level is high and your cortisol level is low, then the adrenal glands are not functioning normally.

ACTH stimulation test. Doctors often will also order an ACTH stimulation test. A medical provider will inject synthetic ACTH into your body. This should cause your adrenal glands to produce cortisol. If it doesn't, it indicates that the adrenal glands are damaged.

Comprehensive metabolic panel. These blood tests check for complications of Addison disease including low blood sugar, high potassium levels, and low sodium levels.

Antibody blood tests. Most often Addison's disease is caused by the immune system making antibodies directed against the adrenal glands. When this occurs, the condition is classified as an autoimmune disease. Doctors order a blood test to specifically look for these antibodies.

Computed tomography (CT) scan. This imaging test can check the size of your adrenal glands to make sure they're not too small or too large. If you have tuberculosis, the test may reveal calcification on your adrenal glands.

Tuberculosis (TB) tests. If no other cause for Addison's disease is found, your medical provider may order tests, such as a TB skin or blood test and chest x-ray, to exclude tuberculosis.

Treating Addison's disease

Addison's disease treatments replace the hormones your body is no longer producing in sufficient quantities. You'll be given a prescription corticosteroid, usually hydrocortisone twice per day, to provide cortisol. If your adrenal glands don't produce enough aldosterone, you'll take fludrocortisone, which balances the amount of sodium and fluid in your body.

Your health care provider will adjust your medication doses as needed. If you're sick, injured, or even under a lot of stress, you may need to temporarily increase your dose. If you're having surgery that requires general anesthesia, you'll also need intravenous (IV) corticosteroids.

Living with Addison's disease

An Addison's disease diagnosis may require dietary changes, and it can be helpful to work with a dietitian.

For example, if you have low aldosterone levels, you may need to follow a high-sodium diet. A dietitian can advise you on how much sodium you need daily, and the best dietary sources to get it from. In addition, most people with Addison's disease take corticosteroids, which raise your risk of developing osteoporosis, a bone disease that makes you more vulnerable to bone fracture. A dietitian can advise you on how much calcium and vitamin D you need, and whether you should take a supplement.

Be alert for an adrenal crisis

It's also important for those with Addison's disease to be aware of signs of an adrenal crisis. Adrenal crisis usually occurs if a person stops taking their hydrocortisone, or they have a significant illness or injury — even if they are taking their usual adrenal replacement doses. In both cases, there is not enough cortisol circulating in the blood to fully support essential bodily functions. Symptoms of an adrenal crisis include:

• nausea and vomiting
• abdominal pain
• marked lightheadedness with standing
• extreme weakness or fatigue
• confusion.

If left untreated, blood pressure can dip so low that you go into shock.

For this reason, people with Addison's disease should always carry the following with them:

• a medical alert necklace or bracelet
• a medical card that lists their medications (including doses) as well as the name and phone number of both their health care provider and an emergency contact
• a medication kit that contains an emergency dose of injectable corticosteroids.

If you develop symptoms of adrenal crisis, give yourself an emergency extra dose of your corticosteroid and then call 911. Once you're at the hospital, you'll get IV injections of corticosteroids and saline.

Most people with Addison's disease live full, healthy lives. If you take your medications as directed and watch for warning signs of adrenal crisis, you'll be able to continue doing all the activities you enjoy.