Everything you need to know about the adrenal glands

The adrenal glands give you the energy to face life’s emergencies, stay calm under pressure, and keep your blood pressure in check.

We explore adrenal gland function, disorders and their symptoms, and the concept of adrenal fatigue.

We cover:

• What are the adrenal glands and what do they do?
• Adrenal gland hormones
• What can go wrong with the adrenal glands?
• Cushing's syndrome
• Addison’s disease
• What is adrenal fatigue?
• How can I check my cortisol level?

What are the adrenal glands and what do they do?
 

The adrenal glands are two triangular-shaped glands that sit on top of each of your kidneys. They form part of the endocrine system, a collection of glands that release hormones to fine-tune many of your body’s processes.

The adrenal glands help regulate:

• Blood pressure
• Development of sexual characteristics
• Immune function
• Metabolism
• Stress response

Each gland is made up of two parts — the cortex (outer region) and the medulla (inner region) — and each of these parts produces different hormones.

What hormones do the adrenal glands make?
 

The outer part (cortex) of the adrenals makes steroid hormones, including cortisol and aldosterone. The inner part (medulla) produces catecholamines — substances the body releases into your blood in response to physical or emotional stress.

 

Hormones produced in the adrenal cortex:

• Cortisol: plays several vital roles, such as helping to control your body’s use of fat, proteins, and carbohydrates. Cortisol also regulates your blood pressure, reduces inflammation, boosts your blood sugar, and helps control your sleep/wake cycle. Your adrenal glands release cortisol in response to stress, which gives you the energy you need to face perceived threats.
• Aldosterone: helps regulate blood pressure, and sodium and potassium (electrolyte) levels in the blood.
• Dehydroepiandrosterone (DHEA) and androgenic steroids: these hormones are converted to male hormones (androgens) in the testes and female hormones (oestrogens) in the ovaries, as well as other tissues in the body.

 

Hormones produced in the adrenal medulla:

• Adrenaline (epinephrine) is a neurotransmitter and hormone released into the bloodstream when you’re in a stressful situation. It causes changes in your body that physically prepare you to deal with perceived threats, including:
  • Causing your heart muscle to contract faster and harder to get more blood to your muscles and brain
  • Increasing blood sugar for energy
  • Relaxing your airways to allow more oxygen to enter your lungs

• Noradrenaline, also known as norepinephrine, is a hormone that has similar effects to adrenaline. It also causes your blood vessels to narrow, increasing blood pressure during times of stress.

 

What can go wrong with the adrenal glands?
 

Adrenal disorders are usually caused by over- or underproduction of adrenal hormones. Some conditions are temporary while others can be lifelong.

 

Causes of adrenal gland disorders include:

• A problem with the hypothalamus or pituitary gland, which both help regulate the adrenals
• Autoimmune diseases
• Benign (non-cancerous) or malignant (cancerous) adrenal gland tumours
• Damage to the adrenal glands, e.g. through injury or infection
• Genetic mutations
• Some steroid medications, such as prednisone and dexamethasone

 

Adrenal gland disorders include:

• Addison’s disease — where there is an underproduction of the adrenal hormones, cortisol and aldosterone
• Adrenal gland suppression — a type of adrenal insufficiency related to external sources of cortisol, such as steroid medications
• Cushing’s disease – where there is an overproduction of cortisol
• Congenital adrenal hyperplasia (CAH) — people with CAH lack enzymes needed by the adrenal glands to make enough hormones
• Hyperaldosteronism — caused by overproduction of aldosterone

What is Cushing’s syndrome?
 

Cushing’s syndrome is a rare condition caused by having too much cortisol in your body.

Causes of Cushing’s syndrome include:

• A pituitary disorder, often caused by a tumour, can lead to the overproduction of adrenocorticotropic hormone (ACTH). This hormone stimulates the adrenal glands to produce cortisol.
• Adrenal gland tumours
• ACTH-producing tumours elsewhere in the body
• Taking steroid medication over a long period (steroids contain a synthetic form of cortisol)

What are the symptoms of Cushing’s syndrome?
 

Cushing’s syndrome symptoms include [1]:

• A fatty hump on the back of the neck and shoulders, known as a buffalo hump
• Increased body fat on the chest and tummy (but slim arms and legs)
• A red, puffy, rounded face
• Purple stretch marks
• A reduced sex drive (low libido)
• Infertility
• Mood swings and depression
• Skin that bruises easily
• Weakness in the upper arms and thighs

How is Cushing’s syndrome diagnosed?
 

Cushing’s can be difficult to diagnose because it shares symptoms with other conditions.

Typically, a diagnosis is made following a series of cortisol tests that measure your levels over the course of a day. You may have cortisol blood tests, or your level can be measured in your urine or saliva.

You may also need other tests or scans to determine the cause of your symptoms. Sometimes a cortisol-mimicking drug is given. In someone without Cushing’s, this would cause a reduction in cortisol, but if someone has the condition, this has little to no effect.

How is Cushing’s syndrome treated?
 

Treatment for Cushing’s depends on what’s causing the overproduction of cortisol.

If it’s caused by taking steroids, your medication dose will be gradually reduced or stopped.

If Cushing’s syndrome is caused by a tumour, treatment may include:

• Surgery to remove the tumour or adrenal glands
• Radiotherapy to destroy the tumour
• Medication to suppress cortisol production (although this is normally a short-term solution)

What is Addison’s disease?
 

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare condition where your adrenal glands don’t produce enough cortisol and/or aldosterone.

It’s usually caused by an autoimmune condition, where the immune system mistakenly attacks the adrenal cortex, disrupting the production of hormones.

Addison's disease can affect people of all ages. However, it’s more common in people aged 30 to 50. Addison’s is also more common in women than in men.

 

There are two types of adrenal insufficiency:

1. Primary adrenal insufficiency is caused by damage to the adrenal cortex, often due to an autoimmune disease.

2. Secondary adrenal insufficiency is normally caused by a pituitary gland problem (usually a tumour). This can reduce ACTH production, which affects levels of cortisol and androgens (aldosterone production is unaffected).

What are the symptoms of Addison’s disease?
 

The early symptoms of Addison’s disease can be similar to other more common health conditions, such as depression or colds and flu.

However, over time, they can become more severe. People with Addison’s must be aware of the risk of a sudden worsening of symptoms, called an adrenal crisis. This can happen when cortisol levels fall significantly.

An adrenal crisis is a medical emergency, and if left untreated, it can be life-threatening.

Symptoms of Addison’s disease include [2]:

• Fatigue
• Hyperpigmentation (darkening of the skin)
• Increased thirst
• Irregular menstrual periods and loss of pubic and underarm hair
• Irritability and depression
• Loss of appetite
• Low blood pressure
• Low blood sugar levels
• Muscle weakness and aches and pains
• Nausea and gastrointestinal problems
• Salt cravings
• Unintended weight loss

How is Addison’s disease diagnosed?
 

Addison’s disease is normally diagnosed by a physical examination, including a blood pressure test, and tests (blood, urine, or saliva) to measure adrenal and pituitary hormone levels.

Cortisol, ACTH, aldosterone, DHEA, sodium, potassium, and glucose levels may all be used to diagnose the condition, as well as distinguish between primary and secondary adrenal insufficiency

Doctors may perform a synacthen test to confirm a diagnosis of adrenal insufficiency. This involves an injection of a synthetic form of ACTH (synacthen). If the adrenal glands are working normally, a blood test taken shortly after the injection should detect a rise in cortisol levels. If there’s no rise, adrenal insufficiency may be the culprit.

An adrenal antibody test can confirm whether an autoimmune disorder is causing the adrenal glands to fail.

How is Addison’s disease treated?
 

Addison’s disease is normally treated with hormone replacement therapy. Hydrocortisone is a synthetic hormone that’s used to replace cortisol. If aldosterone is also affected, a replacement (fludrocortisone) is prescribed alongside a recommendation to increase salt intake, if needed.

What is adrenal fatigue?
 

Adrenal fatigue is a theory that suggests the adrenal glands can become overworked by chronic stress, leading to a mild adrenal insufficiency that causes symptoms.

Adrenal fatigue is not a medically recognised condition and it’s important to see your doctor to rule out other possible causes for your symptoms.

What symptoms are attributed to adrenal fatigue?
 

The symptoms attributed to adrenal fatigue are common and general, meaning they can be found in many other health conditions. They can also happen as part of a normal, busy lifestyle.

Symptoms said to be due to adrenal fatigue include:

• Body aches
• Low mood and depression
• Salt and sugar craving
• Tiredness and fatigue
• Trouble falling asleep at night or waking in the morning
• Weight gain

How is adrenal fatigue diagnosed?
 

There’s no test that can detect adrenal fatigue. Often, a person is told they have it (possibly by an alternative or natural health practitioner) based on their symptoms alone. 

Sometimes, a 24-hour salivary adrenal test may be offered to check adrenal gland function. However, many doctors (including adrenal gland specialists) do not consider these tests appropriate for assessing adrenal function.

What are the risks of being diagnosed with adrenal fatigue?
 

There’s concern amongst doctors that if a person has been told they have adrenal fatigue, the real cause of their symptoms may not be identified and treated.

While there are recognised conditions that affect the adrenal glands, like Addison’s Disease and Cushing’s Syndrome, there’s no scientific proof that chronic stress can lead to adrenal insufficiency.

Problems can arise if symptoms are attributed to adrenal fatigue when they’re early signs of something more serious, or another treatable condition with similar symptoms, like anaemia and thyroid problems.

Before seeking an alternative diagnosis, make sure you talk to your GP to rule out any serious conditions.

How is adrenal fatigue treated?
 

Supporters of adrenal fatigue theory recommend natural treatments like eating well and exercising regularly to improve health. These actions would likely improve your health and wellbeing regardless of your medical diagnosis.

Healthy lifestyle changes that may be recommended for adrenal fatigue include:

• Following a routine for sleeping and waking
• Eating plenty of fruit and vegetables and cutting out ultra-processed foods
• Taking regular moderate exercise
• Quitting smoking

In some cases, practitioners will recommend the use of supplements containing dried adrenal cortex. This may contain the hormone hydrocortisone and can cause symptoms that resemble Cushing’s syndrome if taken in excessive amounts.

How can I check my cortisol level?
 

If you want to check your cortisol level, try our Cortisol Saliva Stress Test. It helps you understand your stress levels and adrenal function by checking your levels of cortisol at four points over the course of a day.

Want more detailed insights into your hormone health but not sure which test to choose? Check out our hormone test buying guides:

• Female Hormone Blood Test Buying Guide
• Male Hormone Blood Test Buying Guide

You can find out more about your hormones in our Hormone Health Hub.

 

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References

1. NHS (2021) Cushing’s syndrome. Available at: https://www.nhs.uk/conditions/cushings-syndrome/ [Accessed 22 August 2024].
2. NHS (2021) Addison’s disease. Available at: https://www.nhs.uk/conditions/addisons-disease/ [Accessed 22 August 2024].