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Health condition · Clinically reviewed

Cushing’s syndrome, cortisol excess - diagnosis and modern treatment.

Cushing’s syndrome means your body has too much cortisol (the main stress hormone) for weeks or months. The cortisol may come from the pituitary gland, an adrenal gland, a tumour elsewhere, or long-term steroid medicines. An endocrinologist first finds the cause. Treatment - surgery or medicines - is then aimed at that cause.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    We check every claim against the Society for Endocrinology, NICE and the Endocrine Society. You can see the sources at the end.

  • 03

    Current for 2026

    Reflects the latest UK guidance on cortisol testing, working out the cause and modern medicines such as osilodrostat.

Key facts

Cushing’s syndrome at a glance.

The essentials, in plain English. What it is, how doctors screen for it, how they find the cause, and how it is treated in the UK today.

In short: Cushing’s syndrome (long-term high cortisol) makes you gain weight around the middle, raises your blood pressure and blood sugar, and thins your bones. UK teams find the cause with cortisol tests and scans, then treat it with targeted surgery or modern medicines.

  • What it is

    Your body sees too much cortisol for too long. This drives weight gain, high blood pressure, diabetes, mood change and thin bones.

  • ACTH-dependent

    A pituitary tumour (Cushing’s disease) or an ectopic tumour makes extra ACTH. The high ACTH then pushes the adrenals to make too much cortisol.

  • ACTH-independent

    The adrenal gland itself makes too much cortisol - from an adenoma, cancer or both glands overgrowing. ACTH is low.

  • Most common cause

    Long-term steroid medicines (tablets, inhalers or creams) are by far the most common cause overall.

  • Diagnosis

    Screening uses a 24-hour urine cortisol test, a late-night saliva cortisol test, or the low-dose dexamethasone suppression test.

  • Prognosis

    Heart and metabolic problems drive the outcome. Early treatment aimed at the cause restores a near-normal life expectancy.

Why this guide matters

A subtle diagnosis with far-reaching effects.

Cushing’s builds up quietly and mimics common problems. It causes serious harm to the heart and metabolism. Spotting it early changes the outcome.

  • Screening tests come first

    Urine, saliva and dexamethasone tests confirm high cortisol before any scan.

  • ACTH tells you where to look

    A low ACTH points to the adrenal gland. A normal or high ACTH points to the pituitary or an ectopic tumour.

  • Surgery is usually curative

    The first-choice treatment is surgery aimed at the cause - pituitary, adrenal or ectopic tumour.

How the diagnosis is made

From first suspicion to cause-directed treatment.

These are the seven steps a UK endocrine team will normally follow, in order. This is so you know what to expect and why.

  1. 01

    Recognising

    Clinical recognition

    A rounded (moon) face, weight around the middle, purple stretch marks, weak thigh and shoulder muscles, high blood pressure and new diabetes raise suspicion.

  2. 02

    Recognising

    Two screening tests

    Doctors use the 24-hour urine cortisol test, the late-night saliva cortisol test and the low-dose dexamethasone suppression test. Two abnormal results are needed.

  3. 03

    Confirming

    ACTH level

    A blood ACTH level shows whether the cause sits in the pituitary or an ectopic tumour (ACTH-dependent), or in the adrenal gland (ACTH-independent).

  4. 04

    Confirming

    MRI pituitary

    A pituitary MRI scan is done if ACTH is not low. Most cases turn out to be a very small pituitary tumour called a microadenoma.

  5. 05

    Confirming

    CT adrenals

    A CT scan of the adrenals is done when ACTH is low. It can find an adenoma, a cancer, or both glands overgrowing.

  6. 06

    Confirming

    Petrosal sinus sampling

    A specialist test called inferior petrosal sinus sampling is done in tertiary centres. It is used when it is still unclear whether the ACTH is coming from the pituitary or elsewhere.

  7. 07

    Managing

    Endocrinology consultation

    An endocrinologist plans surgery or medicines and arranges lifelong follow-up to watch for return of the disease and other health problems.

A typical pathway takes several weeks, from the first screening test to a confirmed cause and a treatment plan.

Symptoms

What Cushing’s syndrome actually looks like.

Signs build up slowly and overlap with common conditions. Comparing recent photos with older ones often shows the change.

  • Central weight gain

    Weight builds up on your tummy and trunk while your arms and legs stay slim. This pattern is a classic clue.

  • Moon face and buffalo hump

    The face becomes rounder and a fat pad forms across the upper back. Cortisol moves fat to these areas.

  • Purple striae

    Wide purple stretch marks appear on the tummy, thighs or arms. They are classic and strongly point to Cushing’s.

  • Proximal muscle weakness

    Climbing stairs or standing up from a chair becomes hard. Cortisol weakens the muscles in your thighs and shoulders.

  • Hypertension

    Blood pressure rises and can be hard to control, even with standard medicines.

  • Diabetes

    You may develop new type 2 diabetes, or find that your usual sugar control gets worse. Cortisol makes the body less sensitive to insulin.

  • Psychiatric symptoms

    Long-term high cortisol can cause depression, anxiety, poor sleep and irritability. Rarely, it causes psychosis.

  • Red flag: severe hypokalaemia

    Very low potassium with severe high blood pressure points to an ectopic ACTH tumour. This needs an urgent specialist review.

Treatment

How Cushing’s syndrome is treated in the UK.

Surgery aimed at the cause is the first-choice treatment. Modern medicines and radiotherapy are used when the disease keeps coming back. Here is what each option does and why the details matter.

  • Transsphenoidal pituitary surgery

    This is the first-choice treatment for Cushing’s disease. A specialist pituitary surgeon removes the tumour through the nose.

  • Adrenalectomy

    The affected adrenal gland is removed, usually by keyhole surgery. This is used for a one-sided adenoma or cancer.

  • Ectopic tumour resection

    The tumour making the extra ACTH - often a bronchial carcinoid or neuroendocrine tumour - is removed once doctors have found it. This can cure the condition.

  • Steroid taper (iatrogenic)

    If steroid medicines caused the problem, doctors lower the dose slowly under supervision. Never stop steroids suddenly - your body needs time to recover its own cortisol.

  • Medical therapy

    Medicines that block cortisol production - ketoconazole, metyrapone, mitotane or osilodrostat - are used before surgery, or when surgery has not cured the disease.

  • Pituitary radiotherapy

    Radiotherapy (either targeted or standard) is used for Cushing’s disease that comes back or does not settle after surgery.

  • Cabergoline

    A dopamine agonist tablet. It is used in some people with residual Cushing’s disease when other treatments are not suitable.

  • Bilateral adrenalectomy

    Removing both adrenal glands is a definitive option for stubborn disease. It cures the high cortisol but you will need lifelong steroid replacement and MRI scans to watch for Nelson syndrome.

What this guide is based on

The sources behind every number on this page.

UK national guidance and specialist society standards. All current at the time of the last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your endocrinologist knows your history and can tell you which parts apply to you. Never stop or change your steroid or cortisol-blocking medicine without specialist advice.

  • Society for Endocrinology. Clinical guidelines on Cushing’s syndrome.

  • NICE CKS. Cushing’s syndrome.

  • Endocrine Society. Clinical practice guideline on the treatment of Cushing’s syndrome.

  • The Pituitary Foundation. Patient information on Cushing’s.

Red flags

When Cushing’s becomes an emergency.

Most Cushing’s care happens in outpatient clinics. These are the situations that need urgent specialist input.

  • Severe hypokalaemia

    Potassium below 3.0 mmol/L, especially with alkalosis and high blood pressure. This needs an urgent search for an ectopic ACTH tumour.

  • Uncontrolled hyperglycaemia

    Blood sugar stays high despite treatment. You need an urgent review by the endocrine and diabetes teams.

  • Diabetic ketoacidosis

    Diabetic ketoacidosis (DKA) in someone with active Cushing’s is an emergency. It needs hospital admission and intravenous insulin.

  • Osteoporotic fracture

    A hip or spine fracture from a minor knock. Doctors will check bone density and start bone-protecting treatment.

  • Severe depression or suicidality

    High cortisol can cause severe mood changes. Please seek urgent mental-health support.

  • Post-surgical adrenal insufficiency

    After curative surgery, your own cortisol supply is low for a while. You will need hydrocortisone tablets and sick-day rules until your body recovers.

  • Nelson syndrome

    A pituitary tumour can grow after both adrenals are removed. Regular MRI scans and specialist review are needed.

  • Cushing’s in pregnancy

    Cushing’s in pregnancy is rare and high-risk. It needs joint care from endocrine and maternal-medicine specialists.

  • Ectopic ACTH malignancy

    A rapid start with severe chemistry changes points to an aggressive tumour. An urgent cancer work-up is needed.

Living with it

After treatment, a steady road back.

Recovery from Cushing’s is slow and steady. Four small things make the biggest difference to how you feel week by week.

A quiet reminder

Recovery is measured in months.

Even after curative surgery, your muscle strength, mood and blood-sugar control take time to rebuild. Steady progress is the norm.

  1. 01 Routine

    Stay on top of your medication

    Take your cortisol-blocking medicines exactly as prescribed. Never change the dose without endocrine advice.

  2. 02 Preparedness

    Know your post-surgical steroid plan

    You will need hydrocortisone tablets after curative surgery until your own cortisol supply recovers. Always carry a steroid emergency card.

  3. 03 Recovery

    Give your body time

    Muscle strength, mood and blood-sugar control get better over months. Expect a slow, steady recovery rather than an overnight one.

  4. 04 Reviews

    Annual endocrine follow-up

    You will have a yearly review. Your team will check your cortisol, heart risk, bone health and how you are feeling.

Frequently asked

Everything we get asked about Cushing’s syndrome.

Quick answers on syndrome versus disease, screening tests, treatment choices, recovery after surgery and when to worry.

  • What is the difference between Cushing’s syndrome and Cushing’s disease?

    Cushing’s syndrome is any cause of long-term high cortisol. Cushing’s disease is a specific type caused by a pituitary tumour that makes extra ACTH. It is the most common cause when the problem comes from inside the body.

  • How is Cushing’s syndrome diagnosed?

    Doctors use two of three screening tests: a 24-hour urine cortisol test, a late-night saliva cortisol test and the low-dose dexamethasone suppression test. A blood ACTH level then shows whether the cause is in the pituitary, an ectopic tumour or the adrenal gland. Targeted scans follow.

  • What is the most common cause?

    Long-term steroid medicines - tablets, injections, inhalers or creams - are the most common cause overall. When the problem starts inside the body, the most common cause is a small pituitary tumour (Cushing’s disease).

  • What treatments are used?

    Surgery aimed at the cause is the first-choice treatment. This means transsphenoidal pituitary surgery for Cushing’s disease, adrenalectomy for an adrenal cause, or removing an ectopic ACTH tumour. Medicines (ketoconazole, metyrapone, osilodrostat or mitotane) are used before surgery, or when surgery does not fully cure the disease.

  • Will I need steroid replacement after surgery?

    Yes. After successful surgery, your own cortisol supply is temporarily low. You will need hydrocortisone tablets until it recovers. This can take many months.

  • When should I seek urgent help?

    Seek urgent endocrine review for very low potassium, high blood sugar you cannot control, a fracture from a minor injury, severe depression or signs of low cortisol after surgery.

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