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.

The adrenal glands are two small, pyramid-shaped glands that sit on top of the kidneys.

Each gland has inner and outer layers, each of which has a separate function:

• the inner area (the medulla) produces the hormone adrenaline
• the outer layer (the cortex) produces steroid hormones

In Addison’s disease, usually the cortex of the both adrenal glands has been destroyed. This disrupts the production of two steroid hormones, called cortisol and aldosterone.

Cortisol is released in stressful situations and helps to maintain your energy levels, your blood sugar levels and carbohydrate metabolism. Aldosterone maintains the balance of salt and water in your body, which helps to control blood pressure.

When the adrenal glands don't produce enough cortisol and aldosterone, symptoms of Addison's disease can appear.

Addison’s disease is usually caused by an autoimmune condition, where the immune system produces antibodies that attack the body. This can damage the adrenal glands and disrupt the production of cortisol and aldosterone.

There is also research to show that people with certain genes may be more likely to develop Addison’s disease, especially those who already have another autoimmune condition, such as diabetes. Other potential causes include conditions that might damage the adrenal glands, such as tuberculosis (TB).

Addison's disease is rare. It is estimated that it affects around 14 people in every 100,000 in the UK. It can affect anyone of any age and both men and women equally.

Read more about the causes of Addison’s disease.

What are the symptoms of Addison’s disease?

At first, the symptoms of Addison’s disease are similar to other more common health conditions such as depression or flu. Dehydration can also be an early sign due to the lack of aldosterone in the body.

Over time, these symptoms may become more frequent, or get worse and you may also experience further symptoms, such as dizziness, fainting, cramps, exhaustion and increasing skin pigmentation.

It is thought that stress such as an illness or accident can also trigger these symptoms, or cause them to get worse.

Read more about the symptoms of Addison’s disease.

Although these aren’t always caused by Addison’s disease, if you have them, see your GP. They may want to confirm or rule out a diagnosis of Addison’s disease.

Treating Addison's disease

Addison’s disease is treated with medication to replace the missing hormones. You will need to take medication for the rest of your life.

The medication is reasonably effective at controlling the 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 in later life, such as heart disease and cancer.

Read more information about living with Addison's disease and how Addison's disease is treated.

If Addison’s disease if left untreated and your levels of cortisol reach dangerously low levels, it can lead to complications such as hypoglycaemia or a situation known as an adrenal crisis.

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 is experiencing severe symptoms, dial 999 to request an ambulance.

Read more about the complications of Addison’s disease.

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, anaemia, an underactive thyroid, chronic fatigue syndrome or flu.

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)
• the need to urinate frequently
• 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, caused by another illness or an accident for example, may cause your symptoms to suddenly get worse.

The symptoms listed above may become more frequent or severe or you may experience further symptoms, such as:

• low blood pressure when you stand up (postural or orthostatic hypotension) 
• dizziness and fainting 
• feeling like you are going to be sick (nausea)
• vomiting and diarrhoea
• abdominal, joint or back pain
• muscle cramps 
• chronic exhaustion, which may cause depression or tearfulness
• brownish discolouration of the skin, lips and gums (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. 

If you're experiencing these symptoms, see your GP so that they can diagnose or rule out Addison’s disease.

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.

During an adrenal crisis the symptoms of Addison’s disease appear very quickly and very severely. This could happen when previous symptoms have been getting worse, or without previous symptoms.

An adrenal crisis is a medical emergency. If left untreated it can be fatal. If you or someone you know have 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

Read more about the complications of Addison’s disease.

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 destroy disease-carrying organisms and toxins). These antibodies will attack the cause of the illness.

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

These immune cells 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, which is sometimes called autoimmune Addison’s disease. In the UK, there are currently around 8,400 diagnosed cases of autoimmune Addison’s disease.

Genetics

Research has shown that if you have certain gene variants (units of genetic material that determine many of your body's characteristics), you may be more likely to have an autoimmune condition. A particular 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 are slightly 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 another 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

Other causes

Tuberculosis (TB) used to be a major health problem in England, 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
• a haemorrhage: very heavy bleeding into the adrenal glands, sometimes associated with meningitis or other severe sepsis
• 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
• surgical removal of the adrenal glands (adrenalectomy), for example to remove a tumour
• a genetic defect with your adrenal glands which means that they do not develop properly or cannot produce hormones

In diagnosing Addison’s disease, your GP will ask you about your symptoms and review your medical history. They are also likely to ask about your family to see if there is any history of autoimmune disorders.

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.

You will also be tested for low blood pressure (hypotension); this will probably 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).

Cortisol tests

If Addison’s disease is suspected, samples of your blood will be tested for the salt levels, sodium and potassium, and the hormone cortisol. A low sodium, a high potassium or a low cortisol level may indicate that you have Addison’s disease.

Blood tests

As well as low cortisol, you may need to see a hospital hormone specialist (endocrinologist) for your blood to be tested for the following:

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

Any of the above could be a sign of Addison’s disease.

Scans

In some cases, your specialist may refer you for a scan of your adrenal gland, which could be a computerised tomography (CT) scan or a magnetic resonance imaging (MRI).

Synacthen stimulation test

If cortisol in your blood is low, or your symptoms alone strongly suggest Addison’s disease, you will need to have a synacthen stimulation test to confirm the diagnosis.

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 and other steroid hormones 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 and 60 minutes, a further blood sample will be taken for cortisol measurement.

If the ACTH level is high, but the cortisol and aldosterone levels are low, 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), 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 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.

Read more about how Addison’s disease is treated.

If you have Addison’s disease, you will need to take daily medication to replace the lost hormones. This should ensure that you can continue to lead a normal life.

Treating the underlying cause

In some 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. This is usually taken in tablet form (orally) once or twice a day.

Synthetic glucocorticoids such as hydrocortisone are used to replace the cortisol. 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 might not be necessary. Unlike most people, if you feel the urge to eat something salty, then you should eat it.

Living with Addison’s disease

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.

You will usually need to have appointments with an endocrinologist every 6-12 months, although your GP can provide support and repeat prescriptions in between these visits. 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 that 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, or go to the MedicAlert website. 

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, dental or medical procedure (e.g. tooth filling, endoscopy)
• you are taking part in strenuous exercise which is not usually part of your daily life

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 endocrinologist 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. Check what out-of-hours services are available from your primary care trust in case the emergency is outside normal working hours.

You can also register yourself with your local ambulance service, so they have a record of your requirement for a steroid injection or tablets, if you need their assistance.

Treating adrenal crisis

Adrenal crisis, or Addisonian crisis, needs urgent medical attention. Dial 999 to request an ambulance if you or someone you know 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.

If Addison’s disease is not diagnosed or is left untreated, there may be serious and potentially fatal complications such as an adrenal crisis.

Adrenal crisis

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. 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.

Read more about the symptoms of an adrenal crisis.

Hypoglycaemia

Hypoglycaemia (low blood sugar) is a symptom of Addison’s disease. If left untreated it can cause unconsciousness, particularly in children. While you are unconscious, your brain will not get enough sugar, which may cause memory loss or even brain damage.

Symptoms of hypoglycaemia can include:

• sweating
• anxiety
• feeling very tired
• difficulty concentrating
• confusion or aggression

Read more about the symptoms of hypoglycaemia.