Addison's disease

Addison's disease, also known as primary adrenal insufficiency or hypoadrenalism is a rare and chronic endocrine disorder of the adrenal glands.^[1] It is named after its discoverer Thomas Addison.^[2]

Addison's disease
Other names	Addison disease, primary adrenal insufficiency,[3] primary adrenocortical insufficiency, chronic adrenal insufficiency, chronic adrenocortical insufficiency, primary hypocorticalism, primary hypocortisolism, primary hypoadrenocorticism, primary hypocorticism, primary hypoadrenalism
Darkening of the skin seen on the legs of an otherwise fair-skinned patient
Medical specialty	Endocrinology
Symptoms	Abdominal pain, weakness, weight loss, darkening of the skin[3]
Complications	Adrenal crisis[3]
Usual onset	Middle-aged females[3]
Causes	Problems with the adrenal gland[3]
Diagnostic method	Blood tests, urine tests, medical imaging[3]
Treatment	Synthetic corticosteroid such as hydrocortisone and fludrocortisone[3][4]
Frequency	0.9–1.4 per 10,000 people (developed world)[3][5]

The adrenal glands are 2 small glands that sit on top of the kidneys. They produce 2 essential hormones: cortisol and aldosterone. Addison's disease is when the body does not produce enough of the hormone called cortisol^[1][6] or aldosterone because the adrenal gland is damaged.^[1] Cortisol helps the body deal with stress. It helps with maintaining blood pressure and controlling the heart's functions. It slows the rate of inflammation caused by the body's immune system. It helps with controlling the way insulin is used, and the chemical reactions of proteins, carbohydrates and fats in the body.

Dark patches of skin caused by Addison's disease

About 9,000 people in the UK have Addison's disease, with over 300 new cases diagnosed each year.^[1] U.S. President John F. Kennedy is probably one of the most famous sufferers though his condition was kept secret during his presidency.

It can affect people of any age, but it is most common between the ages of 30 and 50. It is also more common in women than men.^[1]

Symptoms

People with the disease may suffer from low blood pressure.^[1][6]

Early-stage symptoms of Addison's disease are similar to other more common health conditions, such as clinical depression or flu. Signs and symptoms:^[1]

• lack of energy or motivation (fatigue)^[6]
• muscle weakness^[6]
• low mood
• loss of appetite and unintentional weight loss^[6]
• increased thirst and frequent need to pee
• feeling and being sick
• abdominal pain
• high temperature
• headaches
• difficulty concentrating

Over time, these problems may become more severe. This means further symptoms, such as dizziness, fainting, cramps and exhaustion might occur.^[1]

Signs of small areas of darkened skin,^[6] or darkened lips or gums may develop (hyperpigmentation).^[1]

Although these symptoms are not always caused by Addison's disease, a GP should investigate them.

Adrenal crisis

If the levels of hormones produced by the adrenal gland become too low, it can lead to a life-threatening situation known as an adrenal or Addisonian crisis. This can be triggered by severe physical stress like having an operation or having another illness like an infection.^[1]

During an adrenal crisis, the symptoms of Addison's disease appear quickly and are severe. This could happen when someone is already experiencing initial symptoms or without any symptoms at all. Symptoms of an adrenal crisis include:^[1]

• severe dehydration
• pale, cold, clammy skin
• sweating
• rapid, shallow breathing
• dizziness
• low blood pressure (hypotension)
• severe vomiting and diarrhoea
• abdominal pain or pain in the side
• fatigue and severe muscle weakness
• headache
• severe drowsiness or loss of consciousness

An adrenal crisis is a medical emergency. If left untreated, it can be fatal. Call an ambulance, saying it is an "adrenal crisis" or "Addisonian crisis".

If an adrenal crisis is not treated, it can lead to a coma and death.^[1] There is also a risk that the brain will not get enough oxygen if treatment is delayed, which can cause permanent disability.^[1]

If someone with Addison's disease is having an adrenal crisis, they will need a hydrocortisone injection immediately, either injected by themselves or by a person who is with them^[1] and emergency services.

Causes

Addison's disease develops when the outer layer of the adrenal glands (adrenal cortex) is damaged, reducing the levels of hormones it produces. It may also be caused by:^[1]

• Problems with the immune system

Addison's disease can develop if the immune system attacks the adrenal glands and severely damages the adrenal cortex. When 90% of the adrenal cortex is destroyed, the adrenal glands will not be able to produce enough of the steroid hormones cortisol and aldosterone. Once levels of these start decreasing, symptoms of Addison's disease will appear. It is not clear why some people develop this problem with their immune system, although it can run in families.

• Genetics

It is not obvious how genes lead to Addison's disease and similar conditions. The genes related could be those which affect the immune system or parts or functions of the body affected. Risk is increased with other conditions or family history of the conditions:^[1]

Other causes include:

• vitiligo
• type 1 diabetes
• hypothyroidism

And:^[1]

• tuberculosis (TB), which can spread to other parts of the body
• cancer
• infections (fungal infection, viral infections like AIDS)
• meningitis and sepsis
• haemorrhage (bleeding)
• amyloidosis
• surgery
• treatment for Cushing's syndrome
• adrenoleukodystrophy (ALD). This is a rare, life-limiting inherited condition
• Secondary adrenal insufficiency^[1]

The production of hormones from the adrenal gland can also be affected by damage to the pituitary gland. The pituitary is a pea-sized gland located below the brain that produces a hormone that stimulates the adrenal gland. This is called secondary adrenal insufficiency and is a separate condition to Addison's disease. Secondary adrenal insufficiency can occur if your pituitary gland becomes damaged – for example, because of a tumour on the pituitary gland (pituitary adenoma).

Treatment

Addison's disease is treated with medicine to replace the missing hormones. Aldosterone is replaced with a medicine called fludrocortisone. The GP may also ask someone to add extra salt to their daily diet, although if they are taking enough fludrocortisone medicine this may not be necessary.^[1] Addison's disease is treated by taking an artificial cortisol tablet.^[7] A medicine called hydrocortisone is usually used to replace the cortisol. Other possible medicines are prednisolone or dexamethasone, although these are less commonly used.^[1]

Treatment usually involves corticosteroid (steroid) replacement therapy for life.^[1] Corticosteroid medicine is used to replace the hormones cortisol and aldosterone that the body no longer produces. It is usually taken in tablet form 2 or 3 times a day.^[1]

Some people take dehydroepiandrosterone (DHEA) to improve their stamina or libido (sex drive).^[1]

Related pages

• type 1 diabetes and diabetes insipidus
• hypothyroidism
• corticosteroid
• adrenal gland