Familial hypercholesterolemia — FH — is one of the most common serious genetic conditions there is, affecting roughly 1 in 250 to 300 people. It raises LDL cholesterol and ApoB from birth, and if unrecognised, it substantially increases the risk of early heart disease. The encouraging part: it is highly identifiable and highly treatable — and finding one case is a chance to protect a whole family.
What is FH?
FH is an inherited condition in which the body clears LDL from the blood less effectively, causing very high LDL-C and ApoB from birth. Because that exposure accumulates over a lifetime, untreated FH markedly raises the risk of premature cardiovascular disease. It's diagnosed by a physician using cholesterol levels, family and personal history, and sometimes genetic testing — and, once identified, it's very treatable.
What causes FH
FH is caused by an inherited change in one of the genes that control how the liver removes LDL from the blood — most commonly the LDL receptor gene. With fewer working receptors, LDL particles aren't cleared efficiently, so they accumulate. The result is a high circulating LDL-C and ApoB present from the earliest years of life.
Most people with FH have the heterozygous form (one affected gene copy, inherited from one parent). A far rarer and more severe homozygous form (both copies affected) causes extremely high cholesterol from childhood and needs specialist care.
Why "from birth" is the crucial phrase: cardiovascular risk tracks the cumulative lifetime exposure to atherogenic particles. Someone with FH has been accumulating that exposure since childhood — which is why identifying and treating it early matters so much more than the single number on today's lab report.
How FH is recognised
FH is a clinical diagnosis made by a physician, not something to self-diagnose — but it helps to know the signals that prompt the question. These include:
- Very high LDL-C — markedly above typical ranges, especially if present from a young age.
- A family history of high cholesterol or premature heart disease — a parent or sibling with an early heart attack or stroke.
- Physical signs in some people — cholesterol deposits in tendons (tendon xanthomas) or around the eyes.
Clinicians often combine these into a structured scoring system — such as the Dutch Lipid Clinic Network (DLCN) criteria — that weighs cholesterol level, family history, physical signs, and genetic findings to gauge how likely FH is. Genetic testing can confirm it. Interpreting any of this is a clinician's role; the value of knowing the signals is that they tell you when to ask.
Why FH matters — and why it's hopeful
Untreated, FH carries a high lifetime risk of early cardiovascular disease precisely because the exposure starts so young. But this is one of the more optimistic stories in cardiology: FH is both identifiable (clear signals, confirmable genetically) and treatable (lipid-lowering therapy is highly effective at reducing the particle burden). People with FH who are identified and treated early can have their risk brought much closer to that of the general population.
Common
Roughly 1 in 250–300 people — far more common than most realise, and widely underdiagnosed.
Lifelong from birth
High LDL and ApoB are present from childhood, so exposure accumulates for decades.
Highly treatable
Effective lipid-lowering therapy can dramatically reduce the long-term risk.
A family diagnosis
One case means close relatives are at high risk too — and worth testing.
Family screening: the most important step
Because FH is inherited, a diagnosis in one person is a powerful signal about the rest of the family. Each first-degree relative — parent, sibling, or child — has roughly a 50% chance of also carrying it. This is where cascade screening comes in: when one person is diagnosed, their close relatives are offered testing, and any who are found positive prompt testing of their relatives in turn. It's one of the most effective ways in all of medicine to find high-risk people before they ever have an event.
If FH is identified in your family:
First-degree relatives should be considered for testing — parents, siblings, and children each carry about a 50% chance of also having it.
A simple cholesterol test is the starting point, sometimes followed by genetic testing, arranged through a physician.
Let relatives know — a calm, factual heads-up gives them the chance to check with their own doctors.
What about children?
Because FH is present from birth, screening children in affected families is an established part of FH care in many guidelines — but whether and when to test a particular child depends on the family's specific situation and is a decision to make with your child's doctor. This guide can't and shouldn't set that timing; its role is to explain why the question matters so you can raise it with a clinician who knows your family.
How FH is managed
The goal in FH is to lower the atherogenic particle burden substantially and keep it low for life — reducing the cumulative exposure that drives the risk. Lifestyle helps but is generally not sufficient on its own in FH, so lipid-lowering medication is usually part of the plan. Several classes of therapy are used — statins are typically the foundation, with others added as needed to reach target. Which specific treatment and intensity is right is a decision for you and your physician, guided by your targets and risk. You can read more about the foundation of that treatment in the statins guide, and about the targets themselves in What Is a Normal ApoB Level?
One more marker worth checking: people with FH should also have their Lp(a) measured at least once, since a high Lp(a) on top of FH compounds the inherited risk — and it's a separate, independent factor that FH testing won't reveal.
Common Questions
No. Many people have high cholesterol from diet, weight, or other factors. FH is specifically an inherited condition causing high LDL and ApoB from birth, usually at markedly higher levels and with a strong family pattern. The distinction matters because FH carries higher lifetime risk and is passed to children — which is why it's identified and managed differently.
FH is a genetic condition, so it isn't "cured" — but it is very effectively managed. Consistent lipid-lowering therapy can bring the particle burden down substantially and keep long-term risk much closer to normal. The aim is lifelong control, not a temporary fix.
Not always. FH is often diagnosed clinically — from cholesterol levels, family history, and physical signs, using structured criteria your physician applies. Genetic testing can confirm the diagnosis and is especially useful for cascade screening of relatives, but the clinical picture is frequently enough to act on. Your physician decides what's needed in your case.
Each child of a parent with heterozygous FH has about a 50% chance of inheriting it. That's why testing first-degree relatives is so valuable — it's the only way to know, and finding it early allows protection to start early. Whether and when to test is a conversation for your doctor.
Understand Your Inherited Risk — the Full Picture
CardioIQ reads your ApoB, LDL, and Lp(a) together against longevity-optimal targets — the inherited factors a standard panel can miss — in a physician-grade report you can take to your doctor.
See how CardioIQ reads your panel View a sample report →Important Medical Notice. This article is educational only. It is not medical advice, not a diagnosis, and not a substitute for care from a qualified clinician. Familial hypercholesterolemia is diagnosed and managed by a physician, and decisions about testing — including whether and when to test children or other relatives — should be made with a qualified clinician who knows your family's history. Always consult your physician before making decisions about your health.
References
- Nordestgaard BG, et al. Familial hypercholesterolaemia is underdiagnosed and undertreated in the general population: guidance for clinicians — European Atherosclerosis Society consensus statement. European Heart Journal, 2013.
- 2019 ESC/EAS Guidelines for the Management of Dyslipidaemias. European Heart Journal. doi:10.1093/eurheartj/ehz455
- Dutch Lipid Clinic Network (DLCN) criteria for the clinical diagnosis of familial hypercholesterolaemia.