When someone is told they have high cholesterol, the first reaction is often concern—especially if they’re young or otherwise healthy. One common fear is Familial Hypercholesterolemia (FH), a genetic condition that causes dangerously high levels of LDL (bad) cholesterol from birth.

But here’s the good news: not everyone with high cholesterol has FH. In fact, most people’s elevated cholesterol levels are due to other factors—and they’re often reversible.

Let’s break down the difference between genetic and lifestyle-related cholesterol so you know what to look for and how to take action.

What Is Familial Hypercholesterolemia (FH)?

Familial Hypercholesterolemia is a hereditary disorder caused by a mutation in genes that help clear LDL cholesterol from the bloodstream. As a result, cholesterol levels are high from birth—not just later in life.

Key signs of FH:

• LDL cholesterol levels above 4.9 mmol/L in adults or above 4.1 mmol/L in children.
• A family history of early heart disease—heart attacks or strokes before age 55 in men and 65 in women.
• Possible physical signs like xanthomas (fatty deposits under the skin) or a white ring around the cornea (corneal arcus).
• Limited response to diet and exercise alone—medications are usually necessary.
• Confirmable through genetic testing.

If you meet these criteria, especially if you’re young and otherwise healthy, it’s worth speaking to a doctor about possible genetic causes.

But What If It’s Just Lifestyle-Related?

For the majority of people, high cholesterol is linked to everyday habits—not inherited genes.

Signs your cholesterol may be lifestyle-related:

• It develops in adulthood, often alongside weight gain, poor diet, or lack of exercise.
• Your LDL levels are elevated, but typically in the 3.4–4.9 mmol/L range.
• You don’t have a strong family history of early heart disease.
• You respond well to lifestyle changes—your cholesterol improves with better eating, regular activity, and weight loss.
• No genetic mutations show up in testing (if performed).

How to Tell the Difference

Healthcare professionals look at several factors to distinguish between FH and functional (lifestyle-related) high cholesterol:

• Cholesterol tests (lipid panel): Especially LDL levels.
• Family history: Are your relatives affected, and how early?
• Physical symptoms: FH sometimes shows up visibly.
• Genetic testing: If FH is suspected, testing can confirm it.
• Response to treatment: Lifestyle-related cholesterol often improves without medication.

1. Nordestgaard, B.G., et al. (2013). Familial hypercholesterolaemia is underdiagnosed and undertreated: guidance for clinicians to prevent coronary heart disease. European Heart Journal, 34(45), 3478–3490. https://doi.org/10.1093/eurheartj/eht273 
2. Gidding, S.S., et al. (2015). The Agenda for Familial Hypercholesterolemia: A Scientific Statement from the American Heart Association. Circulation, 132(22), 2167–2192. https://doi.org/10.1161/CIR.0000000000000297 
3. Grundy, S.M., et al. (2018). 2018 AHA/ACC Guideline on the Management of Blood Cholesterol. Journal of the American College of Cardiology, 73(24), e285–e350. https://doi.org/10.1016/j.jacc.2018.11.003 
4. Goldstein, J.L. & Brown, M.S. (2009). The LDL receptor. Arteriosclerosis, Thrombosis, and Vascular Biology, 29(4), 431–438. https://doi.org/10.1161/ATVBAHA.108.179564 
5. Sturm, A.C., et al. (2018). Genetic Testing in the Diagnosis and Management of Familial Hypercholesterolemia. Journal of the American Heart Association, 7(6), e008074. https://doi.org/10.1161/JAHA.117.008074