Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
Familial hypercholesterolaemia
Endocrinology and metabolism · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Escalate
Familial hypercholesterolaemia is usually a prevention diagnosis, but acute coronary syndrome, stroke or limb ischaemia requires the standard emergency pathway immediately. A child or young adult with extreme LDL, early xanthomata or suspected homozygous FH needs urgent specialist lipid assessment because ordinary primary-care statin escalation is insufficient.
Synopsis
Identify inherited LDL elevation before premature vascular disease, confirm the diagnosis through specialist and genetic pathways, and treat the individual while finding affected relatives.
Suspect FH in adults with total cholesterol above 7.5 mmol/L or a personal or family history of premature coronary heart disease, after secondary causes are excluded.
Use Simon Broome or Dutch Lipid Clinic Network criteria in primary care; do not invent a diagnosis from one lipid value alone.
Tendon xanthomata in the patient or a first- or second-degree relative strongly support FH; corneal arcus in a young person is a clue but not diagnostic alone.
Obtain at least two LDL measurements because biological and analytical variation can alter classification, while not delaying treatment in very high-risk disease.
Do not use QRISK to decide whether to treat FH: lifelong LDL exposure creates risk that a ten-year calculator can seriously underestimate.
Refer for DNA testing when clinical criteria support FH; once a pathogenic family variant is known, cascade testing should use that variant rather than cholesterol alone.
Each first-degree relative of a person with heterozygous autosomal-dominant FH has approximately a one-in-two chance of inheriting the variant.
Offer a high-intensity statin aiming for at least a 50% LDL reduction from untreated baseline, then add ezetimibe and specialist therapies when needed.
Children at risk should enter the specialist family pathway, with testing generally completed by age ten and treatment led by clinicians experienced in paediatric FH.
Discuss contraception and pregnancy early; NICE advises stopping lipid-modifying medicines three months before attempting conception and throughout pregnancy and breastfeeding, with specialist exceptions planned individually.
Lifestyle reduces total cardiovascular risk but cannot correct monogenic LDL-receptor dysfunction; never withhold effective medicine because diet is already healthy.
Key red flags
Affected child
A child with high cholesterol plus an affected parent may have heterozygous FH; very early xanthomata or extreme values raise homozygous disease and demand urgent paediatric lipid care.
Homozygous phenotype
Extremely high LDL from childhood, cutaneous or tendon xanthomata before adolescence, aortic-root disease or two affected parents suggests biallelic disease requiring specialist drugs or apheresis.
Investigation priorities
01
Two untreated or best-estimate LDL cholesterol measurementsFirst step
Confirm persistent magnitude and support validated clinical criteria.
Management branches
Case findingRecognise possible FH
An adult has marked cholesterol elevation or premature coronary family history.
Retrieve the highest untreated lipid values, repeat a full profile, examine Achilles and hand tendons and build a three-generation pedigree with ages at coronary events.
Exclude secondary causes and apply Simon Broome or Dutch criteria, remembering that a standard cardiovascular risk score must not determine treatment eligibility.
Refer eligible cases to a lipid or FH service for genetic counselling, DNA testing and a coordinated cascade plan while beginning appropriate LDL lowering.
Key medicines
High-intensity atorvastatin for heterozygous FHStart with a suitable high-intensity once-daily dose, commonly atorvastatin 20 to 80 mg according to baseline LDL, age, interactions and tolerability, then titrate toward at least 50% LDL reduction.Review liver status, strong CYP3A4 interactions, grapefruit and muscle symptoms. Stop three months before planned conception under NICE FH guidance and avoid pregnancy or breastfeeding unless specialist advice changes the plan.
Ezetimibe add-on therapyTake 10 mg orally once daily with the maximally tolerated statin, or alone when statin treatment is contraindicated or genuinely not tolerated under the NICE pathway.Check hepatic function when combined with statin and review ciclosporin, biliary disease and reproductive plans. A modest response does not replace adherence assessment or specialist escalation for very high LDL.
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.