Adrenal Insufficiency
Adrenal Insufficiency
Adrenal insufficiency is a condition in which the body does not produce enough of the hormone cortisol. Cortisol is essential for life and plays an important role in maintaining blood pressure, blood glucose, metabolism, energy levels and the body's response to physical and emotional stress.
For people living with pituitary conditions, secondary adrenal insufficiency is particularly important. It can occur when a pituitary tumour, treatment for a pituitary tumour, or another condition affecting the pituitary gland prevents the gland from producing enough of the hormone ACTH.
Without sufficient ACTH, the adrenal glands are not adequately stimulated to produce cortisol.
Adrenal insufficiency is a potentially serious, lifelong condition when the body's ability to produce cortisol does not recover. However, with appropriate steroid replacement, education and careful management during illness or other stressful situations, people with adrenal insufficiency can lead active and fulfilling lives.
What is adrenal insufficiency?
The adrenal glands are two small glands located above the kidneys. They produce several hormones, including cortisol, which is essential for maintaining normal body functions and helping the body respond to physical stress.
Adrenal insufficiency occurs when the body cannot produce enough cortisol.
There are three main types:
- Primary adrenal insufficiency (Addison's disease) – the problem originates in the adrenal glands themselves.
- Secondary adrenal insufficiency – the problem originates in the pituitary gland, which does not produce enough ACTH to stimulate the adrenal glands.
- Tertiary adrenal insufficiency – the problem originates in the hypothalamus, which normally signals the pituitary gland to produce ACTH.
Although these conditions have different causes, people with adrenal insufficiency are all at risk of becoming seriously unwell if their body does not receive enough cortisol, particularly during illness, injury or other significant physical stress.
Secondary adrenal insufficiency and pituitary conditions
Secondary adrenal insufficiency is the form of adrenal insufficiency most directly associated with pituitary disorders.
The pituitary gland is a small gland located at the base of the brain. Among its many functions, it produces adrenocorticotropic hormone (ACTH).
ACTH acts as a signal to the adrenal glands, telling them to produce cortisol.
If a pituitary tumour or another pituitary disorder damages or interferes with the normal function of the pituitary gland, the production of ACTH can be reduced. This can result in the adrenal glands producing insufficient cortisol.
Secondary adrenal insufficiency can occur in people with pituitary tumours and may also develop following pituitary surgery, radiotherapy or other conditions affecting pituitary function.
The adrenal glands themselves may still be structurally normal, but without adequate ACTH stimulation they cannot produce the amount of cortisol the body requires.
The Pituitary Foundation and Addison's Disease Self-Help Group both identify secondary adrenal insufficiency as the form associated with impaired pituitary ACTH production. (Pituitary Foundation)
What happens to aldosterone?
An important difference between secondary adrenal insufficiency and primary adrenal insufficiency (Addison's disease) is aldosterone.
In primary adrenal insufficiency, the adrenal glands may fail to produce both cortisol and aldosterone. Aldosterone helps the body maintain sodium, fluid balance and blood pressure.
In secondary adrenal insufficiency, aldosterone production is usually preserved, because it is primarily controlled by the renin–angiotensin system rather than ACTH.
As a result, people with secondary adrenal insufficiency generally do not experience the same degree of salt loss and electrolyte disturbance associated with primary Addison's disease. However, they can still develop serious low blood pressure and other symptoms, particularly during an adrenal crisis. (addisonsdisease.org.uk)
Symptoms of adrenal insufficiency
Symptoms can develop gradually and may be difficult to recognise because many overlap with other conditions associated with pituitary disease.
You may experience some, but not necessarily all, of the following:
- Persistent tiredness or overwhelming fatigue
- Weakness or reduced stamina
- Dizziness or light-headedness, particularly when standing
- Low blood pressure
- Loss of appetite
- Unintentional weight loss
- Nausea, vomiting or abdominal discomfort
- Diarrhoea
- Headaches
- Muscle aches, weakness or cramps
- Heaviness or aching, particularly in the legs or lower back
- Feeling cold or shivery
- Difficulty concentrating or "brain fog"
People with primary Addison's disease may also develop increased pigmentation of the skin, particularly in skin creases, scars, gums and other areas. This is generally not a feature of secondary adrenal insufficiency because ACTH is low rather than elevated. (addisonsdisease.org.uk)
Why cortisol is so important
Cortisol is sometimes described as the body's "stress hormone", but it has many essential functions even when we are completely well.
Cortisol helps to:
- Maintain blood pressure and circulation
- Regulate blood glucose
- Support metabolism
- Maintain energy levels
- Help the body respond to infection, illness and injury
- Support the body's response to physical and emotional stress
A healthy adrenal system automatically increases cortisol production when the body is under significant stress.
Someone with adrenal insufficiency cannot make this additional cortisol when it is needed.
This is why steroid replacement and Sick Day Rules are essential.
How is secondary adrenal insufficiency diagnosed?
If secondary adrenal insufficiency is suspected, your GP or Endocrinology team may arrange blood tests to assess your cortisol levels and pituitary function.
Testing may include:
- Morning blood cortisol
- ACTH measurement
- Other pituitary hormone tests
- Electrolytes, including sodium and potassium
- A Short Synacthen Test (ACTH stimulation test)
During a Short Synacthen Test, a blood sample is taken to measure your baseline cortisol level. You are then given synthetic ACTH (Synacthen), followed by another blood sample, usually after approximately 30 minutes.
The test assesses how well your adrenal glands respond to ACTH stimulation. (addisonsdisease.org.uk)
Because pituitary disease can affect several hormones at the same time, your Endocrinology team may also assess other pituitary hormones and functions.
Important: Testing and interpretation of cortisol levels can be affected by steroid medication and other factors. Your Endocrinology team will determine which tests are appropriate and how your medication should be managed before testing.
Treatment
The main treatment for adrenal insufficiency is lifelong glucocorticoid (steroid) replacement when the body's ability to produce cortisol is permanently reduced.
The most commonly used replacement is hydrocortisone, although some people may be prescribed other glucocorticoids such as prednisolone.
Hydrocortisone is normally taken in divided doses throughout the day to more closely reflect the body's natural pattern of cortisol production. The exact medication, dose and timing should be individually determined by your Endocrinology team. (addisonsdisease.org.uk)
For people with secondary adrenal insufficiency, fludrocortisone is not usually required, because aldosterone production is generally maintained.
Never change or stop your steroid replacement medication without medical advice.
Steroid replacement is essential
If you have confirmed adrenal insufficiency, your steroid replacement medication is essential.
Missing doses or suddenly stopping steroid replacement can cause cortisol levels to fall dangerously low and can result in an adrenal crisis, which is a potentially life-threatening medical emergency.
You should ensure that you have an adequate supply of your medication and carry your medication with you when travelling or away from home.
It is also advisable to carry clear medical identification stating that you have adrenal insufficiency and require steroid replacement.
Medical alert jewellery or an appropriate medical alert card can help healthcare professionals recognise the condition quickly, particularly if you are unconscious or unable to communicate.
Steroid Sick Day Rules
When a healthy person becomes ill or suffers a significant injury, their body automatically increases cortisol production to help cope with the additional physical stress.
A person with adrenal insufficiency cannot make this additional cortisol.
Therefore, during illness, injury or other significant physical stress, your usual steroid replacement may not be enough.
This is why people with adrenal insufficiency need to understand and follow Steroid Sick Day Rules, sometimes referred to as stress dosing or steroid updosing.
Depending on the circumstances, this may involve temporarily increasing your oral steroid dose or, if you cannot take or absorb oral medication, receiving emergency hydrocortisone by injection.
Your Endocrinology team should provide you with personalised instructions about:
- When to increase your steroid dose
- How much additional medication to take
- How long to continue the increased dose
- What to do if you vomit after taking your medication
- When to use an emergency hydrocortisone injection
- When to seek urgent medical attention
Sick Day Rules are an important part of living safely with adrenal insufficiency and can significantly reduce the risk of an adrenal crisis. (addisonsdisease.org.uk)
What can trigger an adrenal crisis?
An adrenal crisis can occur when the body's need for cortisol suddenly increases but there is not enough cortisol available.
Possible triggers include:
- Severe infection or illness
- Fever
- Persistent vomiting or diarrhoea
- Being unable to absorb oral steroid medication
- Significant injury or trauma
- Surgery or medical procedures
- Severe dehydration
- Other significant physical stress
- In some circumstances, severe psychological or emotional stress
A relatively minor illness in someone without adrenal insufficiency can become potentially serious in someone who is steroid-dependent. (addisonsdisease.org.uk)
Adrenal Crisis – a medical emergency
An adrenal crisis is a life-threatening emergency caused by an inadequate amount of cortisol.
Symptoms can include:
- Severe weakness or extreme exhaustion
- Severe dizziness or fainting
- Very low blood pressure
- Nausea or vomiting
- Abdominal pain
- Diarrhoea
- Confusion or unusual drowsiness
- Collapse or loss of consciousness
- Dehydration
- Low blood glucose in some people
If an adrenal crisis is suspected, emergency treatment should not be delayed.
Emergency hydrocortisone should be administered as instructed by your medical team, and urgent medical assistance should be sought.
People who have been prescribed an emergency hydrocortisone injection should ensure that they, and ideally family members, partners or carers, know where it is kept and have received appropriate training in how and when to use it.
Emergency hydrocortisone is a critical part of adrenal crisis management. (addisonsdisease.org.uk)
Be prepared
If you live with secondary adrenal insufficiency, it is important to be prepared for emergencies.
Consider carrying:
- Your steroid replacement medication
- An emergency hydrocortisone injection kit, if prescribed
- Medical identification stating that you have adrenal insufficiency
- Written information about your condition and emergency treatment
- Details of your Endocrinology team or GP
It is also important that people close to you know that you have adrenal insufficiency and understand what to do if you become seriously unwell.
Secondary adrenal insufficiency and pituitary tumour
For people living with a pituitary tumour, secondary adrenal insufficiency is an important potential consequence of impaired pituitary function.
A pituitary tumour can interfere with the production of ACTH, while treatment such as surgery or radiotherapy can also affect normal pituitary hormone production.
Not everyone with a pituitary tumour will develop adrenal insufficiency, and the risk depends on the type, size and location of the tumour, the effect it has on normal pituitary tissue, and the treatment received.
Your Endocrinology team can assess your pituitary hormone function and determine whether you require cortisol replacement.
If you have a pituitary condition and have been prescribed steroid replacement, it is important to understand that this medication is replacing a hormone your body may no longer be able to produce adequately.
Living well with adrenal insufficiency
Adrenal insufficiency is a serious condition, but with appropriate treatment, education and preparation, people can continue to live full and active lives.
Understanding your condition is one of the most important ways you can protect yourself.
Make sure you:
- Take your steroid medication exactly as prescribed
- Understand your personal Sick Day Rules
- Carry appropriate medical identification
- Have an emergency hydrocortisone injection if prescribed
- Know how and when to use your emergency injection
- Ensure family members, friends or carers know what to do in an emergency
- Keep an adequate supply of your medication
- Attend regular Endocrinology appointments
- Seek urgent medical attention if you suspect an adrenal crisis
Important
Adrenal insufficiency can be life-threatening if cortisol replacement is not provided when it is needed.
If you have adrenal insufficiency, make sure you have an individual emergency plan agreed with your Endocrinology team.
This information is provided for education and awareness and is not a substitute for personalised medical advice from your GP, Endocrinologist or other healthcare professional.
Further information
For additional information about adrenal insufficiency, steroid replacement, Sick Day Rules and adrenal crisis, see:
- Addison's Disease Self-Help Group (UK) – information on Addison's disease and adrenal insufficiency, medication and Sick Day Rules. (addisonsdisease.org.uk)
- The Pituitary Foundation (UK) – information specifically relating to adrenal insufficiency associated with pituitary conditions. (Pituitary Foundation)
Always follow the individual advice and emergency plan provided by your own Endocrinology team.