Familial Hypercholesterolemia
Familial hypercholesterolemia is a genetic condition that causes very high LDL cholesterol from birth. It is not caused by diet or lifestyle. It is written into your DNA.
Most people with this condition do not know they have it. That is the problem. Without early diagnosis and treatment, the risk of heart attack and stroke rises sharply, sometimes as early as your 30s or 40s.
What Is Familial Hypercholesterolemia?
Familial hypercholesterolemia (FH) is an inherited disorder that prevents the body from clearing LDL cholesterol from the blood. LDL is often called “bad” cholesterol. In people with FH, it builds up inside the arteries from a very young age.
This leads to atherosclerosis, or plaque collecting inside artery walls. Over time, that plaque restricts blood flow and raises the risk of a heart attack or stroke.
FH is not caused by eating too much fat or living an unhealthy life. People with FH are born with high LDL. Their liver cannot remove it from the blood the way a healthy liver does. This distinction matters because lifestyle changes alone are not enough to control it.
At the BaleDoneen Method, identifying inherited risk factors like FH is a core part of preventing heart attacks and strokes before they occur.
Types of Familial Hypercholesterolemia
There are two main types of FH. The difference between them comes down to how many copies of the changed gene a person inherits.
Heterozygous FH (HeFH) is the more common type. It occurs when one parent passes on the gene change. LDL levels are high but not extreme, often in the range of 190 to 400 mg/dL. Most people with FH have this type.
Homozygous FH (HoFH) occurs when both parents pass on the gene change. This is rare, affecting about 1 in 250,000 people. It is far more severe. LDL levels can exceed 400 mg/dL. Without treatment, heart disease can begin before age 10.
Both types increase the risk of early coronary artery disease. The severity and timing depend on which type a person has and how early treatment begins.
Symptoms of Familial Hypercholesterolemia
Mild to moderate FH often causes no symptoms at all. The cholesterol buildup happens silently inside artery walls for years or decades. Many people only find out they have FH after a routine blood test or a heart attack.
As the condition progresses, physical signs and symptoms can develop.
Common physical signs include xanthomas, which are firm lumps of cholesterol that form under the skin on the Achilles tendons, knuckles, elbows, or knees. Xanthelasma are yellowish cholesterol patches that appear around the eyelids. Arcus cornealis is a white or gray ring around the outer edge of the cornea. In people under 45, this ring is often a sign of very high cholesterol.
Later symptoms include chest pain or angina, shortness of breath, pain in the arm or jaw, and reduced tolerance for physical activity. These are signs that plaque has built up in the coronary arteries and is limiting blood flow to the heart.
A heart attack or stroke may be the first noticeable sign of FH in people who have never been tested. See warning signs and symptoms and symptoms in women for what to watch for.
Report very high cholesterol, physical signs like tendon lumps, or a family history of early heart disease to your doctor promptly. Early evaluation leads to better outcomes.
Why Familial Hypercholesterolemia Raises Heart Disease Risk
When LDL receptors on the liver do not work properly, LDL stays in the bloodstream instead of being cleared. This excess LDL circulates through the body and slowly deposits inside artery walls.
Over time these deposits harden and form plaque. Plaque narrows the arteries and reduces blood flow. It also creates conditions that make plaque rupture more likely. A rupture triggers a clot, and that clot can cause a heart attack or stroke.
People with FH have had elevated LDL since birth. By the time they reach their 30s or 40s, decades of cholesterol buildup have already taken place. Untreated FH raises the risk of coronary artery disease by 20 times compared to people without the condition.
This is why FH is so dangerous. It is not the severity of one bad year. It is the accumulation of many years of elevated LDL that begins in childhood.
Causes of Familial Hypercholesterolemia
FH is caused by a change in one of three genes. Each gene plays a role in how the liver removes LDL from the blood.
The LDLR gene codes for LDL receptors on liver cells. These receptors grab LDL from the bloodstream and bring it into the liver for processing. In people with FH, these receptors are missing or do not work properly. LDL remains in the blood.
The APOB gene codes for a protein that helps LDL attach to receptors. A change in this gene means LDL cannot bind properly and stays in circulation longer than it should.
The PCSK9 gene controls how many LDL receptors the liver produces. A change in this gene reduces the number of receptors available, so less LDL gets cleared from the blood.
About 60 to 80 percent of people with FH have a confirmed change in one of these three genes. In others, the genetic cause has not yet been identified, but the condition and its effects are still present.
FH follows autosomal dominant inheritance. One changed gene from one parent is enough to cause the condition. Each child of a parent with FH has a 50 percent chance of inheriting it.
Risk Factors
Key risk factors for developing complications from FH include a family history of early heart attacks, a parent or sibling with FH or very high cholesterol, smoking, high blood pressure, diabetes or insulin resistance, obesity, and high levels of lipoprotein(a).
People with the homozygous form face the highest risk because LDL levels are far more extreme and heart disease can begin in childhood.
Having FH alongside other risk factors compounds the problem. A person with FH who also smokes or has untreated high blood pressure is at significantly greater risk than someone who manages those factors well.
At the BaleDoneen Method, identifying and treating all root causes together, including inflammation, endothelial dysfunction, and genetic risk, is how we work to stop heart disease before it starts.
How Is Familial Hypercholesterolemia Diagnosed?
A lipid panel blood test is the most common starting point. It measures LDL cholesterol levels. Adults with LDL at or above 190 mg/dL and children with LDL at or above 160 mg/dL are assessed for FH. In homozygous FH, LDL can exceed 400 mg/dL.
Genetic testing confirms which gene is affected and helps determine severity. It also allows family members to be tested for the same change through a process called cascade screening, where one diagnosis leads to testing parents, siblings, and children. According to the American Heart Association, cascade screening is one of the most effective strategies for catching FH early across families.
A physical exam may reveal xanthomas, xanthelasma, or arcus cornealis. Family history of early heart disease or very high cholesterol in close relatives also supports a diagnosis.
Additional tools include coronary calcium scoring, CIMT testing, and advanced cardiovascular testing to measure how much plaque has already formed and guide the urgency of treatment. Lipid particle panels provide a more detailed cholesterol picture than a standard blood test alone.
For children with a high-risk family history, screening can begin as early as age 2. All children should have cholesterol checked between ages 9 and 11, and again around age 19.
Treatment and Prevention
Medications are the cornerstone of FH treatment because lifestyle changes alone cannot lower LDL enough in most cases.
Statins are the first line of treatment. They reduce how much cholesterol the liver produces and increase the number of LDL receptors. Statins are effective and well studied. If you experience side effects, other options are available. Read more about statin intolerance.
Ezetimibe lowers the amount of cholesterol absorbed from food in the intestine. It is often added when statins alone do not bring LDL to target levels.
PCSK9 inhibitors are injectable medications that block the protein responsible for reducing LDL receptors on the liver. They are highly effective and are often used when LDL remains high despite statins and ezetimibe.
LDL apheresis is a filtering procedure that removes LDL directly from the blood, similar to dialysis. It is used in severe or homozygous FH when medications are not enough. It is performed on a regular schedule, typically every one to two weeks.
LDL targets for most people with FH and high cardiovascular risk are below 70 mg/dL. For those at very high risk, including people who have already had a heart attack, the target is below 55 mg/dL.
Lifestyle management supports all treatments. A diet low in saturated fat and high in fiber, vegetables, and lean protein helps limit additional cholesterol from food. Learn more about anti-inflammatory nutrition. Regular physical activity supports heart health. Not smoking is essential since tobacco dramatically speeds up arterial damage. Controlling blood pressure, body weight, and blood sugar all reduce the overall risk.
For children diagnosed with FH, statin therapy is often started between ages 8 and 10. Early treatment in childhood slows plaque buildup before it becomes serious.