Addison's disease: symptoms, causes, treatment and adrenal crisis

The adrenal glands are small, triangular glands that sit on top of the kidneys. The Addison's Disease Self-Help Group says they make steroid hormones that keep the body alive and functioning, and that in primary adrenal insufficiency (Addison's disease) the body no longer produces enough cortisol, aldosterone and DHEA. The charity describes cortisol as regulating appetite, blood sugar and food metabolism and as the stress hormone released in response to illness, and aldosterone as regulating sodium, fluid balance and blood pressure.

The NHS describes it as a rare condition where the adrenal glands do not work properly. The charity also explains two related forms, secondary and tertiary adrenal insufficiency, where the problem lies in the pituitary gland or hypothalamus rather than the adrenals. People with those forms usually still produce aldosterone, so they tend to have fewer problems with low blood pressure and salt balance.

The NHS says many symptoms are the same as for other conditions, which is one reason it can be missed. It lists extreme tiredness, skin that is darker than surrounding skin (which may be harder to see on brown or black skin), loss of appetite, weight loss, tummy pain, feeling or being sick and cravings for salty foods, feeling dizzy or light-headed on standing, joint pain, muscle weakness and cramps, headache, a slightly raised temperature, thirst with needing to pee a lot, difficulty concentrating, and anxiety and depression.

The Addison's Disease Self-Help Group lists a similar pattern: overwhelming exhaustion, deepening skin pigmentation that can look like a tan, dizziness on standing, low blood pressure, salt cravings, weight loss, poor appetite, nausea or vomiting, difficulty concentrating, muscle weakness with cramps, headaches and stomach pains. It adds that the darkening may be hard to see on dark skin, so the inside of the mouth and the gums are worth checking.

NICE CKS adds that Addison's disease is sometimes first recognised in a sudden crisis brought on by another illness or stress, which is one reason a GP is advised to consider it in anyone with unexplained collapse, low blood pressure or low sodium.

The NHS says to see a GP if you think you might have Addison's disease.

The NHS says the most common cause is the immune system mistakenly attacking and damaging the adrenal glands. Other causes it lists are congenital adrenal hyperplasia, infections that can damage the glands (tuberculosis, meningitis, flu, cytomegalovirus and HIV) and surgery to remove the adrenal glands. The Self-Help Group also names autoimmune Addison's, infection and bilateral adrenalectomy as causes of primary adrenal insufficiency.

The charity adds that people with other autoimmune conditions, such as Graves' disease, hypothyroidism, type 1 diabetes, pernicious anaemia and vitiligo, have a greater risk of also developing autoimmune Addison's disease.

The NHS says a GP who suspects Addison's disease will refer you to a specialist, usually an endocrinologist (a hormone specialist), though children are often referred to a paediatrician. The specialist asks about your symptoms and you may have a test of how well the adrenal glands are working, using blood samples taken before and after an injection of a medicine called Synacthen, and blood tests to check hormone levels and thyroid function.

The charity explains the short Synacthen test: a baseline blood sample, an injection of ACTH, then a second sample 30 to 60 minutes later to see whether the adrenal glands produce enough cortisol. Extra blood tests measure aldosterone function and look for antibodies that point to the cause.

NICE CKS says that in adults with suspected adrenal insufficiency an 8 am to 9 am serum cortisol blood test is offered, that the diagnosis is confirmed in secondary care with a Synacthen test, and that treatment is started and adjusted by a specialist endocrinologist.

The NHS says there is currently no cure but medicines can manage the condition. They replace the steroid hormones the body is missing and may include hydrocortisone, prednisolone and fludrocortisone. The Self-Help Group explains that people with primary adrenal insufficiency also take fludrocortisone because they lose aldosterone, the sodium-retaining hormone.

You will usually take medicine every day for the rest of your life, and it is important never to run out. The NHS says you may need extra medicine when unwell, before surgery or during stressful periods such as exams, and your specialist will advise on this. It says to carry a steroid emergency card at all times, which tells healthcare professionals that you have Addison's disease and take steroid medicine that should not be stopped suddenly, and notes that you can also get medical jewellery. Do not change doses on your own.

The charity says most people take hydrocortisone in divided doses through the day, with the first dose being the largest to mirror the body's natural rhythm, and that fludrocortisone is taken once or twice a day. NICE CKS says people should be given advice on increasing steroid cover during physical stress such as illness, injury or surgery to prevent adrenal crisis.

On sick days the charity warns that vomiting, diarrhoea, colds and flu can trigger an adrenal crisis in anyone who is steroid dependent, and that early signs of a bug should prompt an adjustment of steroid replacement in line with the sick day rules your specialist has given you.

The NHS says adrenal crisis is the most serious complication, when symptoms get worse very quickly. It can be triggered by an infection, an accident or injury, or surgery, and can cause severe dehydration, low blood pressure, seizures, loss of consciousness, stroke and cardiac arrest. It can usually be treated with an injection of steroid medicine, and you should be given an emergency kit so you can give the injection yourself; your specialist may also train you or your carer.

The NHS says to call 999 if you have Addison's disease and symptoms suddenly get worse or you have a fast heart rate, feel very dizzy or light-headed, have severe tummy or side pain, muscle weakness, pain or spasms, a headache that does not go away, nausea or vomiting, feel very drowsy, irritable or confused, have a seizure or lose consciousness. It is important to call 999 even if you have given yourself the emergency injection.

The NHS calls it a serious condition that can be challenging to live with, because you must remember the medicine every day and there may be times when you need emergency treatment. You will have appointments with your specialist to discuss symptoms, how well the medicine is working and how confident you feel managing the condition. The Self-Help Group says that with the right balance of daily medication people can expect a normal lifespan.

The NHS says it is very important that Addison's disease is well managed during pregnancy, otherwise it can cause serious problems including an increased risk of miscarriage, and that if you are planning a pregnancy your specialist can advise you. Your care team passes information to the National Congenital Anomaly and Rare Disease Registration Service, and you can opt out.

Diagnosis and lifelong follow-up usually sit with an NHS endocrinology team. A private endocrinologist can offer a quicker specialist opinion if the diagnosis is in doubt, but the same safety arrangements apply: an emergency kit, a steroid card, and a clear plan agreed with whoever prescribes your medicines for how to adjust doses when ill.