Addison's disease

Published by Bupa's Health Information Team, February 2011.

This factsheet is for people who have Addison's disease, or who would like information about it.

Addison's disease is a rare condition in which the adrenal glands become damaged. This stops the body from producing hormones that usually help control blood pressure, fight off infections and regulate blood sugar level.

About Addison's disease

You have two adrenal glands, one on each side of your body, located just above your kidneys. Each adrenal gland has an inner core (the medulla) and an outer shell (the cortex).

If you have Addison's disease, the cortex of your adrenal glands becomes irreversibly damaged or destroyed. The cortex usually produces the hormones:

• cortisol, which increases your blood sugar level and helps to maintain energy levels so you can respond to stressful situations
• aldosterone, which regulates the salt and water levels in your body, helping to control blood pressure
• some 'sex hormones', including dehydroepiandrosterone – this can be converted to hormones including oestrogen and testosterone

When your adrenal gland becomes damaged in Addison's disease, your body can't produce enough of these hormones. You will need lifelong treatment with replacement hormones.

Addison's disease is a rare condition, only affecting about one in every 10,000 people. You can get the condition at any age, but it's most common between 30 and 50 and more women than men get it. Many people live with the disease and are unaware that they have it for a long time.

Symptoms of Addison's disease

If you have Addison's disease, you may get symptoms that include:

• extreme tiredness
• weakness
• loss of appetite and weight loss
• feeling the need to urinate frequently
• feeling thirsty
• cravings for salty food
• dizziness/fainting when you stand up
• feeling sick and vomiting
• pain in your muscles and joints
• a brownish colour to your skin, particularly on your face and hands and on any recent scars
• headaches
• abdominal (tummy) pain
• feeling low
• if you're a woman, loss of pubic hair and the hair in your armpits, and irregular periods

These symptoms aren't always caused by Addison's disease but if you have them, see your GP.

Complications of Addison's disease

An Addisonian crisis (or adrenal crisis) is one of the most serious potential complications of Addison's disease. This happens when your supply of hormones becomes dangerously low for your body's needs.

This can happen if your body is under intense stress, for example, if you’re having surgery, have a major illness or injury, or are fighting off a serious infection. Usually when your body is under stress your adrenal glands produce more hormones to help your body cope. In Addison's disease, your adrenal glands can't cope with the added stress.

Even if you're already being treated for Addison's disease, you may still have an Addisonian crisis if you develop vomiting or diarrhoea, as this may prevent your body from absorbing your medicines properly.

Warning signs of an Addisonian crisis are similar to untreated Addison’s disease and include:

• feeling very sick
• a headache
• dizziness
• extreme tiredness
• confusion
• fever

If you have these signs, you may go into shock - this is when your blood pressure becomes very low and there isn't enough oxygen getting around your body. This is an emergency and you should seek urgent medical attention.

Causes of Addison's disease

Addison's disease is caused when your adrenal cortex is damaged. In the UK and other developed countries, the most common reason for this is an autoimmune condition. This means it's caused by antibodies from your immune system attacking your body. In Addison's disease, your immune system attacks your adrenal glands so that they can't produce hormones.

Many people with Addison's disease also have another autoimmune disorder, such as a thyroid disorder or diabetes, or are likely to develop one in the future.

Research has shown that there may be a genetic (inherited) link to Addison's disease. If you have a certain gene (inherited 'building block'), you may be more likely to have an autoimmune condition. Exactly how this gene affects the development of Addison's disease isn't yet known, but it does suggest that there is a 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 in your life.

Other rarer causes of Addison's disease include:

• tuberculosis (this is a common cause in developing countries)
• other infections, including HIV/AIDS and fungal infections
• surgical removal of your adrenal glands – for example, if they were removed because of a tumour
• cancer of your adrenal glands
• an injury to your adrenal glands, such as in a car accident

Diagnosis of Addison's disease

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.

Your GP may test your blood pressure to see if it's low. You will be asked to have blood checks and tests to confirm if you have Addison's disease. The main blood test measures how much cortisol your body can produce.

Your GP may refer you to an endocrinologist - a doctor who specialises in conditions that affect your endocrine system (your body's hormones). Additional blood may be taken to measure other substances in your blood, such as aldosterone.

You may also need to have a CT scan or an MRI scan of your adrenal gland. A CT scan uses X-rays to make a three-dimensional image of your body. An MRI scan uses magnets and radiowaves to produce images of the inside of your body.

Treatment of Addison's disease

If you have Addison's disease, you will need to have treatment for the rest of your life to replace the hormones that your body is no longer making. Your doctor will prescribe the following medicines.

• Hydrocortisone or another synthetic steroid – this replaces the hormone cortisol. It's taken as a tablet, usually in two or three doses throughout the day.
  
• Fludrocortisone – this is a tablet that replaces aldosterone. You will usually only need to take this once a day in the morning.

Your doctor will also prescribe an injectable form of hydrocortisone to use in emergencies, for example, if you're feeling sick or have had an accident or other severe injury. This will prevent you having an Addisonian crisis. Your doctor will supply a sterile syringe and needle, and your practice nurse will teach you or a friend or relative how to inject the hydrocortisone.

The exact dose of hydrocortisone and fludrocortisone tablets you need will be individual to you. You may need to have a number of tests to find the right dose for you, including blood pressure checks and blood tests to see how long the hydrocortisone stays in your body.

At certain times, you may need to increase your dose – for example if you have a fever, or if you're having surgery or dental work done. Your doctor will give you advice on when you should do this, but for most illnesses that you treat at home you will need to double your hydrocortisone dose.

Some doctors may also prescribe dehydroepiandrosterone for women with Addison's disease who have depression or a low sex drive. However, there isn't any evidence at present to show that this is effective.

You will probably have appointments with your endocrinologist every six to 12 months. Your GP will provide regular healthcare and support in between these visits, and can prescribe repeat medication for you.

Living with Addison's disease

If you have Addison's disease, with the right balance of medicine you can expect to live as long as someone without the condition and lead a full and productive life.

However, it's very important to remember that the medicines you take are essential for life. Here are some tips to help you manage your condition.

• Never stop taking your medicine suddenly.
• Always carry spare medicine.
• Renew your repeat prescription in plenty of time, and always keep a month's spare supply.
• When you go on holiday, make sure you have twice as much medicine as you would usually need with you, as well as your emergency injection supplies and an emergency crisis letter (available from Addison’s Disease Self Help Group). Carry medicine in your hand luggage when flying, as well as a note from your GP to explain why you need to have the medication and needles – you may need to pay for this letter.
• Wear an ID bracelet or necklace that states you have Addison's disease or carry a steroid card, so that in an emergency medical staff will be aware of your condition.
• Tell any doctor treating you about your condition.
• Let your GP know if you notice any new symptoms, as it might mean you need to adjust your medicine.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.