What Is Familial Hypercholesterolaemia?
Familial hypercholesterolaemia — often shortened to FH — is an inherited condition that causes high levels of low-density lipoprotein (LDL) cholesterol from birth. Unlike the gradual cholesterol changes that many people develop through decades of diet and lifestyle, FH is written into a person's DNA. The body's ability to clear LDL cholesterol from the bloodstream is impaired from day one.
LDL cholesterol is often called "bad" cholesterol because excess amounts can build up in artery walls, narrowing them over time and raising the risk of heart attack and stroke. In people with FH, this exposure begins in childhood and continues unchecked unless the condition is identified and managed.
FH is more common than many people realise — affecting approximately 1 in 250 individuals. Despite this, the majority of those with the condition have never been diagnosed. Many discover it only after a heart event in their 40s or 50s, or when a routine blood test returns unexpectedly high results.
LDL Cholesterol
Low-density lipoprotein cholesterol, often called "bad" cholesterol, is a fatty substance that can build up in artery walls and increase the risk of heart disease when levels are too high.
Autosomal Dominant
A pattern of inheritance where a single copy of an altered gene is enough to cause a condition. Each child of an affected parent has a 50% chance of inheriting it.
LDLR Gene
A gene that carries instructions for making LDL receptors on liver cells. Variants in this gene are the most common cause of familial hypercholesterolaemia.
Cascade Testing
A systematic approach to screening the close relatives of a person newly diagnosed with an inherited condition, to identify others who may have it but don't yet know.
Xanthoma
A fatty deposit that forms under the skin, most often around tendons, caused by excess cholesterol in the blood. It can be a visible clue to conditions like FH.
Homozygous FH
A rare and severe form of familial hypercholesterolaemia that occurs when a person inherits an FH-causing gene variant from both parents, rather than just one.
This article is for general health information only and is not a substitute for personalised medical advice. If you have concerns about your cholesterol or family history, please speak with a qualified healthcare professional.
How It Is Inherited
FH follows what geneticists call an autosomal dominant inheritance pattern. This means that inheriting just one faulty copy of a relevant gene — most commonly the LDLR gene, which provides instructions for LDL receptors — is enough to cause the condition. Variants in the APOB and PCSK9 genes are less common causes.
When one parent has FH, each of their children has a 1-in-2 (50%) chance of inheriting the same variant. The condition does not skip generations. If both parents carry an FH-causing variant — a much rarer situation — a child may inherit two faulty copies, resulting in a far more severe form called homozygous FH.
Understanding inheritance patterns can help explain why heart disease appears to cluster in some families. As described in our article on heart disease and family history, a pattern of early cardiovascular events across relatives is worth discussing with a doctor — it may signal an underlying inherited cause such as FH.
It is also worth noting that FH is distinct from other inherited conditions that carry cardiovascular implications. You can explore how different genetic conditions compare in our overview of family health history.
Recognising the Signs and Getting Diagnosed
FH is often called a "silent" condition because raised LDL cholesterol produces no obvious symptoms for many years. When physical signs do appear, they include:
- Xanthomas: fatty deposits that form under the skin, typically around tendons in the hands, feet, or Achilles tendon
- Xanthelasmas: yellowish patches of cholesterol that appear around the eyelids
- Corneal arcus: a pale arc or ring around the iris of the eye, particularly notable before age 45
However, many people with FH never develop these visible signs. Diagnosis typically comes through a blood test showing persistently high LDL cholesterol, assessed alongside personal and family medical history using recognised clinical scoring tools.
Talk to Your Doctor About Cascade Testing
If you have been diagnosed with FH, ask your healthcare provider whether cascade testing is available in your area. Many lipid clinics can help coordinate screening for your immediate family members. Early identification means earlier treatment — and a significantly reduced risk of heart disease over a lifetime.
Genetic testing can confirm a specific variant but is not always required for a clinical diagnosis. If FH is suspected in a family, cascade testing — systematically offering cholesterol screening to close relatives of a confirmed case — is the most efficient way to identify undiagnosed individuals. Early detection matters enormously because cholesterol accumulates in artery walls over decades.
Managing FH Day to Day
FH cannot be cured, but it can be effectively managed. The goal is to reduce LDL cholesterol to a level that lowers long-term cardiovascular risk. Management typically involves a combination of medical treatment and lifestyle measures, tailored by a clinician to the individual.
Medical Treatment
Cholesterol-lowering medications — statins being the most widely used — are a cornerstone of FH management. They work by reducing the liver's production of cholesterol and increasing the clearance of LDL from the blood. Other medication classes may be added when statins alone are insufficient. Dosing, choice of medication, and monitoring frequency are decisions made by a healthcare provider based on individual circumstances.
Do Not Stop Medication Without Medical Guidance
Cholesterol-lowering medications for FH are typically prescribed as a long-term commitment, not a short-term fix. Stopping or adjusting medication without consulting your doctor can allow LDL levels to rise again, increasing cardiovascular risk. Always discuss any concerns about side effects or treatment with your prescribing clinician.
Lifestyle Measures
While lifestyle changes alone cannot correct the underlying genetic impairment, they remain an important complement to medication. A diet lower in saturated fat, regular physical activity, not smoking, and maintaining a healthy weight all contribute to cardiovascular health. As explored in our article on how lifestyle and genetics interact, genetics set a predisposition — lifestyle choices influence where within that range a person lands.
Why Family Awareness Matters
One of the most powerful aspects of an FH diagnosis is what it can mean for the rest of the family. A single confirmed case creates an opportunity to identify relatives who may also be living with undetected high cholesterol — often for years before any symptoms arise.
Having an open conversation with first-degree relatives (parents, siblings, children) about a new FH diagnosis is a meaningful step. Many healthcare systems offer support through lipid clinics or genetic services that can coordinate cascade testing. Children of an affected parent can be screened early, and if FH is confirmed, management can begin in childhood — substantially reducing lifetime cholesterol exposure.
FH shares something important with other inherited conditions: awareness within a family can genuinely change outcomes. Just as knowledge of hereditary cancer risk can guide earlier screening, understanding FH in a family context empowers relatives to act before damage accumulates. Our article on hereditary cancer syndromes and family history explores similar themes in a different health context.
FH Patient Registries and Support Organisations
Several countries have national FH registries and patient advocacy groups that offer educational materials, peer support, and guidance on accessing cascade testing. Searching for a national lipid or FH association in your country is a practical first step.
Cardiovascular Risk Assessment Tools
Clinicians use validated scoring systems — such as the Dutch Lipid Clinic Network criteria — to assess the likelihood of FH. Asking your doctor about formal risk assessment can help clarify whether further investigation or genetic referral is appropriate for you.
If you or someone in your family has been diagnosed with FH, the most important step is to work with a healthcare professional to understand your individual risk, establish a management plan, and discuss who else in the family might benefit from testing.
This article provides general health information and is not intended as medical advice. Always consult a qualified healthcare professional for guidance specific to your health situation.
