What causes Addison’s disease?
The adrenal glands are small triangular shaped glands that sit on top of your kidneys. Their job is to produce the hormones that keep the body functioning properly. One of these hormones is called cortisol. It regulates the body’s metabolism, keeping blood pressure and blood sugar in check. Cortisol is released by the adrenal glands throughout the day. If stressed or ill, the adrenal glands produce more cortisol to make sure the body keeps functioning correctly. Another hormone called aldosterone regulates sodium and fluid balance. Lastly, DHEA is a hormone that influences stamina and libido.
In people who have adrenal insufficiency, the adrenal glands stop working properly and aren’t able to produce these hormones, which are crucial to keeping our body functioning correctly. This can be caused by any of a number of conditions, including:
1. Addison's disease. This is where the adrenal glands themselves stop working. It is also called primary adrenal insufficiency or primary Addison's disease. Often, this is caused by the body’s immune system making a mistake and attacking and destroying the cells of the adrenal glands in error. This type of Addison’s is called autoimmune Addison’s.
Addison's can also be caused by an infection (such as tuberculosis or HIV) damaging the adrenal glands. Occasionally, a person may need to have their adrenal glands removed. This is called a bilateral adrenalectomy and is another cause of primary adrenal insufficiency.
2. Pituitary disease. The pituitary is a small pea sized gland in your head that produces a hormone called ACTH that tells your adrenal glands what to do. If the pituitary gland stops sending these hormone signals, the adrenal glands don’t work properly and can't produce the hormone, cortisol. This is called secondary adrenal insufficiency. People with this condition usually still produce aldosterone, meaning they usually have fewer problems with low blood pressure and disturbed salt levels than people with primary Addison's disease.
3. Genetic. In some people, there is a mistake in the spelling in their genetic code, meaning the adrenal glands are unable to manufacture the necessary hormones. One such condition is congenital adrenal hyperplasia (CAH), where there is a spelling error in the gene responsible for producing a protein that helps to generate cortisol in the adrenal glands; as a result, cortisol and often aldosterone levels are low. Another condition that causes of adrenal insufficiency is X-linked adrenoleukodystophy (ALD) or adrenomyeloneuropathy (AMN). This affects boys and men and can cause both adrenal insufficiency and neurological symptoms.
While the conditions listed above have different causes, people who live with them day-to-day experience similar challenges regarding their steroid dependency, resulting from the inability of their adrenal glands to produce cortisol. They need to take steroid medication every day to stay healthy. Much of the information on this website – particularly regarding steroid treatment and emergency experiences – is relevant to people who are steroid-dependent from any cause of adrenal insufficiency, not just those with primary Addison's disease.
How common is Addison’s disease?
Addison’s disease affects approximately 1 in 10,000 people, meaning an estimated 300 - 350 new cases are diagnosed each year across the UK. This makes it roughly 300 times rarer than diabetes, another endocrine condition that sometimes occurs alongside Addison’s. Diagnosis is most common between the ages of 30 – 50, but can occur at any age.
What are the signs and symptoms of Addison’s disease?
People with adrenal failure typically report some or all of the following symptoms:
- overwhelming exhaustion
- weight loss
- deepening skin pigmentation (looking like they a sun tan even when they haven’t been out in the sun)
- dizziness on standing
- low blood pressure
- poor appetite
- nausea or vomiting
- difficulty concentrating
- muscle weakness with cramps
- salt cravings
- stomach pains
As it can be an autoimmune condition, people with Addison’s disease may have other autoimmune conditions either themselves or present in their immediate family. These can include thyroid disorders, diabetes, vitiligo, coeliac disease or B12 deficiency.
How is Addison’s disease diagnosed?
Diagnosis is done by hospital blood tests and an assessment of the symptoms. Suspected cases will be referred to see an endocrinologist, a doctor who specialises in treating hormone-related conditions. The main blood test used is called the short Synacthen test (also known as an ACTH stimulation test or a cosyntropin test). This measures the ability of your adrenal glands to produce cortisol and involves two blood samples being taken. The first is a ‘baseline’ reading to measure how much cortisol is in your blood when at rest. You are then given an injection of a hormone called ACTH (this is the hormone normally produced by your pituitary gland to instruct your adrenal glands what to do) and a second blood sample is taken 30-60 minutes after this. If the adrenal glands are healthy, cortisol production in the second sample will exceed a certain level, commonly 500-550 nmol/L. By contrast, adrenal glands that aren’t working properly will not be able to produce this amount of cortisol.
Additional hospital blood tests will measure your aldosterone function. These are plasma renin, sodium & potassium tests. A further antibody blood test to establish the cause of your adrenal failure is recommended. If this is negative, an adrenal scan and other tests may be needed. You can read more about how Addison's disease is diagnosed in the Society for Endocrinology: adrenal insufficiency patient booklet.
How is Addison’s disease treated?
People with Addison’s disease will need to take daily steroid medication to keep their bodies functioning well for the rest of their lives. This medication replaces the hormones that their adrenal glands can no longer make.
Most people take their steroid medication three times a day, starting when they first wake up and then at five to six hourly intervals in the day. The amount and type of medication varies a lot from patient to patient and depends upon the type of adrenal insufficiency they have been diagnosed with and their individual needs. Together with their endocrinologist, they should work out a medication schedule that suits them. Common medication include:
- Hydrocortisone – this medication is given to replace cortisol and is usually taken in three divided doses throughout the day
- Fludrocortisone – this medication replaces aldosterone and is usually taken in one or two daily doses
People with Addison’s should also be prescribed an emergency injection kit in case of adrenal crises (see below or the emergency section of our website).
It is essential that people with Addison’s take their medication every day, at the right time of day – this is essential for life. They should also receive ongoing medical support, with regular appointments with their endocrinologist to review their condition. As Addison’s disease is a rare condition, sometimes other medical professionals such as GPs or nurses aren’t very familiar with it or with the need for daily steroid medication. The ADSHG has a number of publications that provide guidance to these healthcare professionals on what support people with Addison’s will need.
What is life like for people with Addison’s disease?
Although Addison’s is a life-long condition, it can be treated successfully with replacement hormones. People with Addison’s can have a normal life span and lead full and active lives. The ADSHG has members who live well into their 90s.
You can visit the sporting achievements section of our website to read more about the achievements of people with Addison’s. Those with exceptional fitness have competed in international gymnastics, climbed Mont Blanc or run the London marathon. Although extra planning is needed, Addison’s need not be a barrier to living life to the full.
What is an adrenal crisis?
An adrenal crisis occurs in people with Addison’s when the cortisol present in their body is not sufficient to keep it functioning. Common triggers include:
- other infections, for example, flu
- extreme emotional stress
An adrenal crisis is a life-threatening situation and requires immediate medical treatment. The person needs to be given an emergency injection of hydrocortisone straight away. If you are a family member or close friend of a person with Addison’s, you may find it useful to learn how to give this injection in case of emergency. You can read more about this in the emergencies & hospitalisation section of our website or visit our video hub.
Where can I find out more information about Addison’s disease?
There is a wealth of information available on this website. Some of our most popular sections are listed below:
- Publications for people with Addison's
- Video hub
- Emergencies & hopsitalisation section
- Educational resources for schools, colleges and media
There are also some external sources of information you may find useful:
- Society for Endocrinology adrenal insufficiency patient booklet
- Adrenal insufficiency – how to spot this rare disease and how to treat it
- Addison's disease - NHS Choices
- Addison's disease (You and your hormones, a public information website produced by the Society for Endocrinology)