Health condition
Cyclical Cushing's
Cyclical Cushing's is a rare form in which cortisol excess comes and goes in waves, so tests taken in a quiet phase can be normal - repeated testing timed to symptoms is the key.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Cortisol production rises and falls, sometimes over weeks or months, with symptoms flaring and settling
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Normal test results during a quiet phase do not exclude it
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Late-night salivary cortisol collected repeatedly at home is the most practical way to catch a peak
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Keep a symptom diary and test during flares - weight, bruising, flushing and mood often track the cycles
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Specialist: an endocrinologist experienced in Cushing's, ideally within a pituitary centre
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
In cyclical Cushing's the tumour driving cortisol - usually pituitary, occasionally adrenal or ectopic - switches on and off. Patients describe unmistakable waves: rounding of the face, ankle swelling, bruising, insomnia and agitation building over weeks, then fading. Because a single normal dexamethasone suppression test or urine collection during a trough can be falsely reassuring, this diagnosis is frequently missed or dismissed.
Diagnosis and treatment routes
The workaround is repetition: sequences of late-night salivary cortisol samples or 24-hour urine collections gathered at home across good and bad spells, reviewed by an endocrinologist who takes the pattern seriously. Once cortisol excess is proven in a peak, the source is traced in the standard way. If you suspect cycling and have been told tests are normal, a specialist review is reasonable; private endocrinology appointments are typically available within about two weeks, against NHS routine waits often exceeding 20-45 weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant endocrinologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Cyclical Cushing's.
Quick, plain-English answers to what people ask us most.
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What is cyclical Cushing's syndrome?
Cyclical Cushing's syndrome is a form of Cushing's syndrome in which cortisol levels rise and fall periodically, rather than remaining continuously high, making both symptoms and diagnosis more variable and challenging.
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What causes cyclical Cushing's syndrome?
It's caused by the same underlying sources as other Cushing's syndrome - typically a pituitary or adrenal tumour - but with cortisol production that fluctuates over time rather than staying constantly elevated, for reasons that aren't always fully understood.
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What are the symptoms of cyclical Cushing's syndrome?
Symptoms are similar to standard Cushing's syndrome (weight gain, easy bruising, muscle weakness, high blood pressure) but may come and go or fluctuate in intensity, sometimes making the condition harder to recognise consistently.
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Is cyclical Cushing's syndrome dangerous?
Yes, like other forms of Cushing's syndrome, ongoing cortisol excess (even if fluctuating) carries risks of high blood pressure, diabetes, and osteoporosis, so it needs proper diagnosis and treatment despite the diagnostic challenge.
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Why is cyclical Cushing's syndrome hard to diagnose?
Because cortisol levels fluctuate, a single test performed during a 'low' phase can appear normal, potentially missing the diagnosis - which is why repeated testing over time is often needed to catch the condition during an active phase.
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How is cyclical Cushing's syndrome diagnosed?
Diagnosis typically requires repeated cortisol testing (such as urine or salivary cortisol) over an extended period to capture the cyclical pattern, since a single test may not be conclusive.
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How is cyclical Cushing's syndrome treated?
Treatment depends on identifying and addressing the underlying cause, similar to other Cushing's syndrome - surgery for a pituitary or adrenal tumour, or medication to control cortisol production if surgery isn't immediately possible.
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Can cyclical Cushing's syndrome be cured?
When a tumour is identified and successfully removed, cure is possible, similar to standard Cushing's syndrome, though the cyclical nature can make confirming full resolution more challenging and may need extended follow-up.
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Cyclical vs standard Cushing's syndrome - what's the difference?
Standard Cushing's syndrome involves continuously elevated cortisol, while cyclical Cushing's syndrome shows fluctuating cortisol levels over time - the cyclical pattern specifically requires repeated testing to confirm rather than a single test.
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When should I see a specialist if cyclical Cushing's is suspected?
See an endocrinologist if you have fluctuating symptoms suggestive of Cushing's syndrome, even if a single test has been normal. A private endocrinology consultation experienced in this diagnostic challenge is often available within about two weeks.