Addison's disease

Page last reviewed: 13/07/2011

Addison's disease (also known as primary adrenal insufficiency or hypoadrenalism) is a rare disorder of the adrenal glands. It affects the production of two hormones - cortisol and aldosterone - which help to regulate blood pressure.

Adrenal glands

The adrenal glands are two small, triangular-shaped glands that sit on top of the kidneys, high up inside the back of the abdominal wall.

Each gland has an inner and outer layer that have separate functions:

  • the inner area (the medulla) produces the hormone adrenaline, and
  • the outer layer (the cortex) produces steroid hormones and small amounts of the male and female sex hormones, testosterone and oestrogen

In Addison's disease, usually the cortex of the both adrenal glands is destroyed. This disrupts the production of steroid hormones, cortisol and aldosterone.

Cortisol

Cortisol belongs to a group of hormones called glucocorticoids. It is often called the stress hormone because it is released in stressful situations. Cortisol helps you to cope by invoking the fight or flight feelings. It also has several other functions, including:

  • maintaining blood pressure and heart function
  • suppressing the immune system
  • maintaining your blood glucose (sugar) levels
  • regulating your metabolism (the process that turns food into energy)

Aldosterone

Aldosterone is part of a group of hormones called mineralocorticoids. It maintains the balance of salt and water in the body by helping the kidneys keep hold of the sodium in the blood, while removing the potassium. If the kidneys cannot do this properly, the volume of blood falls. If there is less blood being pumped around the body, blood pressure will drop.

When cortisol and aldosterone are not produced in sufficient amounts, it can cause the symptoms of Addison's disease.

How common is Addison's disease?

Addison's disease is rare. For example, one study estimated that it affects about 14 people in every 100,000.

Addison's disease can be diagnosed at almost any age and it affects both men and women equally.

Outlook

If left untreated, the amount of steroid hormones in the body will gradually fall and the symptoms of Addison's disease will get progressively worse. Eventually, this will cause an adrenal crisis (when the symptoms become very severe and blood pressure drops to a very low level). An adrenal crisis can be fatal if it is not treated immediately.

Once Addison's disease has been diagnosed, it is possible to treat using medication to replace the missing hormones. The medication will be required for the rest of your life.

The medication will be reasonably effective at controlling your symptoms, although there may be times, particularly when you are feeling stressed or under pressure, where you experience tiredness, lethargy (a lack of energy), depression and, in women, a reduced libido (sex drive).

Due to advancements in treatment, the average life expectancy for people with Addison's disease has improved significantly over the last 50 years and is now similar to the population at large. However, people with Addison's disease do have a higher than average risk of developing serious conditions, such as heart disease and cancer, in later life. 

 

Disease

A disease is an illness or condition that interferes with normal body functions.

Kidneys


Kidneys are a pair of bean-shaped organs located at the back of the abdomen, which remove waste and extra fluid from the blood and pass them out of the body as urine.

Blood


Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Adrenaline


Adrenaline is a hormone produced at times of stress that affects heart rate, blood circulation and other functions of the body.

Heart

The heart is a muscular organ that pumps blood around the body.

Metabolism

Metabolism is the process the body uses to build and maintain itself. It involves breaking down food and nutrients to produce energy.

Steroids

Steroids are types of chemicals found naturally in the body. They are also produced artificially to treat diseases.

Glucose

Glucose (or dextrose) is a type of sugar that is used by the body to produce energy.

Immune system

The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.

Testosterone

Testosterone is a male sex hormone, which is involved in making sperm and sexual characteristics such as the voice getting deeper. Testosterone is also found in small amounts in women.

Deficiency

If you have a deficiency it means you are lacking in a particular substance needed by the body.

 

Page last reviewed: 13/07/2011

The initial symptoms of Addison's disease, such as tiredness, a lack of energy and muscle weakness, are similar to the symptoms of many other health conditions, such as depression, flu or chronic fatigue syndrome

Initial symptoms

Dehydration can be an early sign of Addison's disease. It is caused by the lack of the hormone aldosterone in your body, which is used to regulate the balance of salt and water.

Other initial symptoms of Addison's disease include:

  • fatigue (lack of energy or motivation)
  • lethargy (abnormal drowsiness or tiredness)
  • muscle weakness
  • low mood (mild depression) or irritability
  • loss of appetite and unintentional weight loss
  • low blood pressure (hypotension)
  • increased thirst
  • craving for salty foods
  • hypoglycaemia (low blood sugar)

Progressive symptoms

The symptoms of Addison's disease tend to develop gradually over time. However, any additional stress, such as another illness or an accident, may cause your symptoms to suddenly get worse.

The symptoms listed above may increase in frequency or severity, and you may experience further symptoms such as:

  • postural or orthostatic hypotension (low blood pressure when you stand up)
  • dizziness and fainting (a sudden, temporary loss of consciousness)
  • nausea (feeling like you are going to be sick)
  • vomiting and diarrhoea
  • abdominal, joint or back pain
  • muscle cramps (when your muscles suddenly shorten for a few seconds or minutes and you cannot control them)
  • chronic exhaustion, which may cause depression or tearfulness
  • brownish discoloration of the skin (hyperpigmentation), particularly in the creases on your palms, on scars or on pressure points, such as your knuckles or knees
  • in women, a reduced libido (a lack of interest in sex)

Symptoms such as sweating and, very occasionally,psychosis occur but are unusual. Some women may also have irregular periods or miss some periods completely. 

Adrenal crisis

If Addison's disease is left untreated, the levels of cortisol and aldosterone in the body will gradually decrease. This will cause the symptoms to get progressively worse and eventually lead to a situation that is known as an adrenal crisis.

Adrenal crisis or Addisonian crisis is where the symptoms of Addison's disease show very quickly and very severely. This could happen when the above symptoms have been getting progressively worse, or it may occur without any previous symptoms.

An adrenal crisis is a medical emergency. If left untreated it can be fatal. If you, or someone you know has Addison's disease and experience any of the symptoms listed below, dial 999 to request an ambulance.

The symptoms of an adrenal crisis are: 

  • severe dehydration
  • severe hypotension
  • Shock(when your organs and tissues are not receiving enough blood)
  • severe vomiting and diarrhoea
  • extreme muscle weakness
  • headache
  • extreme sleepiness or coma
  • death

Glossary

Fatigue
Fatigue is extreme tiredness and lack of energy.
Pain
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Constipation
Constipation is when you pass stools less often than usual, or when you are having difficulty going to the toilet because your stools are hard and small.
Blood
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Dehydration
Dehydration is an excessive loss of fluids and minerals from the body.

Page last reviewed: 13/07/2011

Addison's disease is caused when your adrenal cortex (the outer layer of your adrenal glands) is damaged. The most common reason for this is an autoimmune condition.

Autoimmune conditions

Your immune system is your body's defence against infection and disease. If you are ill, your immune system will start to produce antibodies (a special type of protein to neutralise or destroy disease-carrying organisms and toxins). These antibodies will attack the cause of the illness.

If you have an autoimmune condition, your immune system starts producing antibodies that attack your own tissues and organs.

These antibodies can cause Addison's disease if they start to destroy your adrenal cortex. If 90% of the adrenal cortex is destroyed, your adrenal glands will not be able to produce enough of the steroid hormones, cortisol and aldosterone. Once the levels of these start decreasing, you will start to experience the symptoms of Addison's disease.

In the developed world, autoimmune conditions cause around 80% of all cases of Addison's disease. Addison's disease that is caused by autoimmune conditions is sometimes called autoimmune Addison's disease. 

Genetics

Research has shown that if you have certain genes (units of genetic material that determine many of your body's characteristics), you may be more likely to have an autoimmune condition. A particular allele (a piece of DNA coding) has been found in a number of people with autoimmune Addison's disease that is also present in people with other autoimmune disorders.

Exactly how this gene contributes to the development of Addison's disease is not yet clear, but it does enforce the link between Addison's disease and other autoimmune conditions. Therefore, if you have another autoimmune condition, you may be more likely to develop Addison's disease at some point.

Research has suggested that up to half of all people with autoimmune Addison's disease will have more than one autoimmune condition. Some of the more common autoimmune conditions that have been linked to Addison's disease are:

vitiligo a chronic (long-term) condition that causes pale, white patches to develop on the skin

type 1 diabetes: a chronic condition that is caused by too much glucose in the blood  

  • hypothyroidism ,an underactive thyroid gland
  • hyperthyroidism, an overactive thyroid gland

Other causes

(Tuberculosis TB) used to be a major cause of death in Ireland, and it still is in some parts of the developing world. TB is a bacterial infection that mostly affects the lungs but it can also spread to other parts of your body. TB can cause Addison's disease if it destroys your adrenal glands.

Some other possible causes of Addison's disease include:

  • infections: such as those that are linked to AIDS, or fungal infections such as ringworm
  • a haemorrhage: very heavy bleeding into the adrenal glands
  • cancer: if cancer cells from elsewhere in your body spread to your adrenal glands
  • amyloidosis: a disease where amyloid, a protein that is produced by the cells in your bone marrow, builds up in your adrenal glands and damages them
  • adrenalectomy: surgical removal of the adrenal glands, for example to remove a tumour
  • a genetic defect with your adrenal glands: this means that they do not develop properly or cannot produce hormones

Glossary

Immune system
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.

Page last reviewed: 13/07/2011

In diagnosing Addison's disease, your GP may review your medical history and ask about your family to see if there is any history of autoimmune disorders. Your GP will also ask you about your symptoms and how they affect your everyday activities. For example, you may have problems carrying heavy bags of shopping or walking up stairs.

Your GP will examine your skin for any evidence of hyperpigmentation (brownish discolouration of the skin). This will be particularly noticeable where your skin creases on your palm or in your elbow, and also on any scars. However, hyperpigmentation does not occur in all cases of Addison's disease.

Your blood pressure will be taken to see if it is low. It might be measured while you are sitting down and again shortly after you stand up. This is to see whether you have postural or orthostatic hypotension (low blood pressure when you change position). See low blood pressure for more information.

Cortisol tests

If your GP suspects that you have Addison’s disease, they may take an early morning sample of blood from a vein in your arm.  The sample will be tested for the hormone cortisol.  A low cortisol level may indicate that you have Addison’s disease.

Blood tests

As well as low cortisol, your blood can also be used to look for the following:

  • a low level of aldosterone
  • a high level of adrenocorticotrophic hormone (ACTH, see below)
  • a low level of sodium
  • a high level of potassium
  • a low level of glucose (sugar used for energy)

Any of the above could be a sign of Addison's disease. If cortisol is low, or your symptoms alone strongly suggest Addison's disease, you will need to have a synacthen stimulation test to confirm the diagnosis.

Synacthen stimulation test

Your GP may refer you to an endocrinology unit (a unit that specialises in the study of hormones) for a synacthen stimulation test. How urgently you are referred will depend on how severe your symptoms are.

Synacthen is a synthetic (man-made) copy of the adrenocorticotrophic hormone (ACTH). ACTH is naturally produced by the pituitary gland (a pea-sized gland below the brain) to encourage the adrenal glands to release the hormones cortisol and aldosterone. When synacthen is administered, the adrenal glands should respond in the same way as they would to ACTH, and release cortisol into the blood.

A blood sample will be taken and tested for the level of cortisol. Synacthen will then be given by an injection into your arm. After 30 minutes, another blood sample will be takento measure cortisol.

If the ACTH level is high but the cortisol levels were low during the synacthen test with a low aldosterone levels, it is usually confirmation of Addison’s disease

Thyroid function test

As well as a synacthen stimulation test, your thyroid gland may also be tested to see if it is working properly. Your thyroid gland is found in your neck. It produces hormones that are released into the bloodstream to control your body's growth and metabolism (the process that turns the food you eat into energy).

People with Addison's disease often have an underactive thyroid gland (hypothyroidism), which is where the thyroid gland does not produce enough hormones. By testing the levels of certain hormones in your blood, your endocrinologist (a specialist in hormone conditions) can determine whether you have hypothyroidism.

Diagnosis during an adrenal crisis

During an adrenal crisis, your blood pressure will be dangerously low, and your symptoms will be very severe. In this situation, there is not enough time to perform a synacthen stimulation test to confirm Addison's disease.

If possible, blood will be taken and tested for any of the signs listed above. While you are waiting for the results, treatment may be started with fluids containing salt and glucose before Addison's disease is diagnosed.

Glossary

Corticosteroids
Corticosteroid is a naturally occurring hormone produced by the adrenal gland, or a synthetic hormone having similar properties. It is used to reduce inflammation, so reducing swelling and pain.
Blood
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

How cortisol is normally produced

  • A tiny part of the brain called the hypothalamus sends corticotrophin-releasing hormone (CRH) to the pituitary gland (an organ at the bottom of the brain).
  • The pituitary gland then produces adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands (two small organs located above the kidneys).
  • The adrenal glands release the hormone cortisol into the bloodstream.
  • In Addison’s disease, the adrenal gland cannot produce cortisol.
  • The level of ACTH in the blood remains high but the level of cortisol in the blood remains low.
  • The production of cortisol can be tested using a man-made copy of ACTH called synacthen.
  • Synacthen is injected into the blood. After waiting 30 minutes to an hour, a blood sample is taken to be tested.
  • If there is ACTH in the blood but no cortisol, Addison’s disease will be confirmed.

Page last reviewed: 13/07/2011

Treating the underlying cause

In most cases, the underlying causes of Addison's disease can be treated. For example, tuberculosis (TB) is treated with a course of antituberculous medication over a period of at least six months.

Other infections may be treated with antibiotics or antifungal medication, as necessary. Autoimmune conditions will be treated, although they cannot usually be cured.

Treating Addison's disease

In the majority of cases of Addison's disease, treatment will involve corticosteroid (steroid) replacement therapy, which is ongoing for life. Corticosteroid medication is used to replace the cortisol and aldosterone that your body no longer produces. These are usually taken in tablet form (orally) once or twice a day.

Synthetic glucocorticoids are used to replace the cortisol. This is usually hydrocortisone. Other possible medicines are prednisolone or dexamethasone, though these are less commonly prescribed. 

Aldosterone is replaced with oral doses of a mineralocorticoid, called fludrocortisone. Your GP may also ask you to add extra salt to your daily diet, although if you are taking enough fludrocortisone medicine this should not be necessary.

Addison's disease should not affect your quality of life or how long you live. Your diet, exercise and daily routine can all continue as normal. As long as you take your medication, the symptoms of Addison's disease should completely disappear.

However, failing to take your medication could cause an adrenal crisis. Therefore, you must:

  • remember to collect your repeat prescriptions
  • keep spare medication as necessary - for example, in the car or at work and always carry some spare medication with you
  • take your medication every day at the right time of day
  • pack extra medication if you are going away - usually, double what you would normally need and your injection kit (see below, under emergency treatment) just in case you become ill
  • carry your medication in your hand luggage, if you are travelling by plane, with a note from your doctor explaining why it is necessary

You could also inform close friends or colleagues of your condition, and warn them about the risks of adrenal crisis.

Medical alert bracelets

It is also a good idea to wear a medical alert bracelet or necklace that informs people that you have Addison's disease.

After a serious accident, such as a car crash, your body should produce cortisol. This helps you to cope with the stressful situation and the additional strain on your body that results from serious injury. As your body cannot produce cortisol, you will need a hydrocortisone injection to replace it and prevent an adrenal crisis.

If you are wearing a medical alert bracelet, it will inform any medical staff who may need to treat you about your condition and what medication you require.

Medical alert bracelets or necklaces are pieces of jewellery that are engraved with your medical condition, in this case Addison's disease, as well as an emergency contact number. They are available from a number of retailers. Ask your GP if there is one that they recommend,

If you need to stay in hospital, the healthcare professionals who are responsible for your care will also need to know that you need steroid replacement medication throughout your treatment.

Adjusting your medication

At certain times, your medication may need to be adjusted to take into account any additional strain on your body. For example, you may need to increase the dosage of your medication if you experience any of the following:

  • an illness or infection - particularly if you have a high temperature of 37.5C (99.5F)
  • an accident
  • you need to have an operation
  • you are taking part in some strenuous exercise

This will help your body to cope with the additional stress. Your GP will monitor your dosage and advise you about any changes. Over time, as you get used to the condition and learn what can trigger your symptoms, you may learn how to adjust your medication yourself. However, always consult your GP if you are unsure.

Emergency treatment

You and a partner or family member may be trained to administer an injection of hydrocortisone in an emergency. This could be necessary if you go into shock after an injury, or if you experience vomiting or diarrhoea and are unable to keep down oral medication. This may occur if you are pregnant and have morning sickness.

Your GP will discuss with you when an injection might be necessary. You will be given needles, syringes and hydrocortisone, and training in how to use them.

If you need to administer emergency hydrocortisone, always call your GP immediately afterwards.

Treating adrenal crisis

Adrenal crisis or Addisonian crisis (see the Symptoms section) will need urgent medical attention. Dial 999 to request an ambulance if you are experiencing adrenal crisis.

You will be given lots of fluid through a vein in your arm to rehydrate you. This will contain a mixture of salts and sugars (sodium, glucose and dextrose) to replace those that your body is lacking. You will also be injected with hydrocortisone to replace the missing hormone, cortisol.

Any underlying causes of the adrenal crisis, such as an infection, will also be treated.

Glossary

HRT
Hormone replacement therapy or HRT involves giving hormones to women when the menopause starts, to replace those that the body no longer produces.

Page last reviewed: 13/07/2011

Hypoglycaemia

(Hypoglycaemia low blood sugar) is a symptom of Addison's disease. It can cause unconsciousness, particularly in children. While you are unconscious, your brain will not get enough oxygen, which may cause brain damage.

Low levels of cortisol

If you have not yet been diagnosed with Addison's disease, you may not realise that your body is low in the hormone cortisol. Cortisol helps your body to cope with the effects of stress, by maintaining your blood pressure and heart function.

If you are low in cortisol, and you have a stressful experience, such as a surgical operation, or a severe injury or infection your body may not be able to cope. You could start to experience adrenal crisis (see the Symptoms section). This is also possible if you lose too much salt from your body through bleeding or sweating.

Adrenal crisis can be fatal and will require urgent medical attention.

Complications from adrenal crisis

Adrenal crisis is a medical emergency and must be treated immediately. If it is left untreated, it can lead to coma and death. Adrenal crisis can cause:

  • cardiac arrest: when the heart stops completely
  • Stroke when the blood supply to the brain is interrupted
  • hypovolaemic shock: when severe blood and fluid loss means that your heart cannot pump enough blood around your body
  • hypoxia: when the body's tissues do not get enough oxygen

If any of your organs or tissues, including your brain, do not get enough oxygen, it can cause permanent disability.

Glossary

Stomach
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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