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.
All human beings have two adrenal glands, one on each side of the body, located just above the kidneys. Each adrenal gland has an inner core (the medulla) and an outer shell (the cortex). In Addison's disease, the cortex of the adrenal glands becomes irreversibly damaged or destroyed. The cortex usually produces hormones like cortisol, which increases the 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 the body, helping to control blood pressure; and some 'sex hormones'.
When the adrenal gland becomes damaged in Addison's disease, the body can't produce enough of these hormones. You will need lifelong treatment with replacement hormones.
Addison's disease affects about one in every 10,000 people. You can get the condition at any age, but it is 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.
The symptoms of Addison’s disease 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 the muscles and joints
- - a brownish colour to the skin, particularly on the face and hands and on any recent scars
- - headaches
- - abdominal (tummy) pain
- - feeling low
- - if you’re a woman, loss of pubic hair and hair in the armpits, and irregular periods
An Addisonian crisis (or adrenal crisis) is one of the most serious potential complications of Addison's disease. This happens when the supply of hormones becomes dangerously low for the body's needs. This can happen if the 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 the body is under stress the adrenal glands produce more hormones to help the body cope. In Addison's disease, the adrenal glands cannot 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 the body from absorbing the medicines properly. The warning signs of an Addisonian crisis are similar to untreated Addison’s disease and include feeling very sick, headaches, dizziness, extreme tiredness, confusion and fever. If you have these signs, you may go into shock – this is when the blood pressure becomes very low and there isn’t enough oxygen getting around the body. This is an emergency and you should seek urgent medical attention.
Addison’s disease is caused when the adrenal cortex is damaged. The most common reason for this is an autoimmune condition which means that it is caused by antibodies from the immune system attacking the body. In Addison's disease, the immune system attacks the adrenal glands so that they cannot 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 the life.
Other rarer causes of Addison's disease include:
- - tuberculosis (a common cause in developing countries)
- - other infections, including HIV/AIDS and fungal infections
- - surgical removal of the adrenal glands – for example, if they were removed because of a tumour
- - cancer of the adrenal glands
- - injury to the adrenal glands, such as in a car accident
You may be referred to an endocrinologist – a doctor who specialises in conditions that affect the endocrine system (the body’s hormones). Additional blood may be taken to measure other substances in the blood, such as aldosterone. You may also need to have a CT scan or an MRI scan of the adrenal gland. A CT scan uses X-rays to make a three-dimensional image of the body. An MRI scan uses magnets and radiowaves to produce images of the inside of the body.
If you are diagnosed with Addison’s disease, you will need to have treatment for the rest of your life to replace the hormones that the body is no longer making. The doctor will prescribe a hydrocortisone or another synthetic steroid which replaces the hormone cortisol and/or fludrocortisone, a tablet that replaces aldosterone. The 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.
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 the body. At certain times, you may need to increase the dose – for example if you have a fever, or if you’re having surgery or dental work done. The 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 the hydrocortisone dose.
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 the condition:
- - Never stop taking the medicine suddenly.
- - Always carry spare medicine and keep a month’s supply ready.
- - When you go on holiday, make sure you have twice as much medicine as you would usually need with you.
- - Carry medicine in the hand luggage when flying, as well as a note from the doctor to explain why you need to have the medication and needles.
- - Keep an ID on you at all times stating that you have Addison’s disease, so that in an emergency medical staff will be aware of the condition.
- - Tell any doctor treating you about the condition.
- - Let the doctor know if you notice any new symptoms, as it might mean you need to adjust the medicine.