Health condition
Familial hypocalciuric hypercalcaemia
Familial hypocalciuric hypercalcaemia (FHH) is a benign inherited calcium-sensing disorder that perfectly mimics primary hyperparathyroidism on blood tests - the crucial difference is that FHH needs no surgery, ever.
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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Caused by variants in the calcium-sensing receptor (CASR) gene; lifelong, mildly raised calcium with normal wellbeing
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Blood tests look like hyperparathyroidism: raised calcium with normal or mildly raised PTH
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The separator: a 24-hour urine calcium-to-creatinine clearance ratio below 0.01 suggests FHH
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Family testing helps - relatives with lifelong mild hypercalcaemia support the diagnosis, and genetic testing confirms it
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Parathyroid surgery does not cure FHH and should not be offered
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
The calcium-sensing receptor is the body's calcium thermostat; FHH resets it a notch higher. Calcium runs mildly elevated from birth, the kidneys conserve rather than excrete it, and the person is well - no stones, no bone disease, no symptoms attributable to the level. The condition matters almost entirely because of what it can trigger: misdiagnosis as primary hyperparathyroidism, futile neck exploration and the removal of innocent glands.
Diagnosis and treatment routes
Every hypercalcaemic workup should therefore include a 24-hour urine collection: a very low calcium clearance ratio points to FHH, childhood or family calcium records strengthen it, and CASR gene testing settles it, extending reassurance to relatives through cascade testing. Management is documentation and reassurance - flagging the diagnosis so no future clinician reaches for a scalpel. If you or a family member has unexplained mild hypercalcaemia, an endocrine opinion is sensible; private appointments are typically available within about two 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 Familial hypocalciuric hypercalcaemia.
Quick, plain-English answers to what people ask us most.
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Can you explain what familial hypocalciuric hypercalcaemia is?
Familial hypocalciuric hypercalcaemia refers to a recognised clinical condition that a GP or specialist assesses using your history, examination and, if appropriate, targeted investigations. The way it presents and its impact can vary considerably from person to person.
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What causes familial hypocalciuric hypercalcaemia?
Familial hypocalciuric hypercalcaemia can arise from several different underlying mechanisms, and in many cases more than one factor contributes. Identifying likely causes usually forms part of the initial specialist work-up.
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What does familial hypocalciuric hypercalcaemia look like?
Symptoms of familial hypocalciuric hypercalcaemia vary from person to person and can range from mild and easily missed to significant enough to affect daily life. Because overlapping conditions can produce similar symptoms, a clinical assessment is the most reliable way to confirm what's actually going on.
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Can familial hypocalciuric hypercalcaemia cause complications?
Most cases of familial hypocalciuric hypercalcaemia are manageable with appropriate care, though, like many conditions, it can occasionally lead to complications if left unassessed or untreated. Your clinician can give you a realistic sense of the risks based on your specific presentation.
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Is familial hypocalciuric hypercalcaemia hereditary or genetic?
Many forms of familial hypocalciuric hypercalcaemia have a genetic or inherited component, and some are linked to specific gene changes that can run in families. If there's a family history, genetic counselling can help clarify the pattern of inheritance and whether relatives might benefit from testing.
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Is there a cure for familial hypocalciuric hypercalcaemia?
Familial hypocalciuric hypercalcaemia can often be managed effectively, and in some cases prevented or reversed, with the right combination of lifestyle changes, medication or other targeted treatment. A specialist will tailor the approach to your circumstances rather than applying a one-size-fits-all plan.
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How is familial hypocalciuric hypercalcaemia treated?
Treatment for familial hypocalciuric hypercalcaemia is usually built around the severity of your symptoms and any underlying cause found on assessment, and may involve lifestyle measures, medication, physiotherapy or, in some cases, a procedure. Your specialist will discuss the pros and cons of each option with you before agreeing a plan.
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What's the outlook for familial hypocalciuric hypercalcaemia?
The outlook for familial hypocalciuric hypercalcaemia varies widely depending on the underlying cause, how early it's diagnosed, and how it responds to treatment. Many people see significant improvement with appropriate care, and your specialist can give you a more personalised timeframe once they've reviewed your case.
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Could familial hypocalciuric hypercalcaemia be confused with another condition?
Because several conditions can share similar symptoms to familial hypocalciuric hypercalcaemia, clinicians often consider a short list of possibilities before confirming a diagnosis. This is one of the main reasons a proper assessment, and sometimes targeted tests, matters more than relying on symptoms alone.
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When should I see a doctor about familial hypocalciuric hypercalcaemia, and how quickly can I be seen privately?
It's worth seeking medical advice if symptoms of familial hypocalciuric hypercalcaemia are persistent, worsening, or affecting your daily life, rather than waiting for them to resolve on their own. NHS routine referrals for this kind of assessment can take anywhere from around 20 to 45+ weeks, whereas private consultants typically offer an appointment within about two weeks.