Optimize
← All biomarkers
Heart & Vascular

LDL Cholesterol

LDL cholesterol is the cholesterol in your blood that can lodge in artery walls and build up as plaque.

What is LDL Cholesterol?

LDL cholesterol is the amount of cholesterol carried inside LDL particles — the lipoproteins that move cholesterol from the liver to the rest of the body. On a standard lipid profile, LDL is usually calculated rather than directly measured. When triglycerides are high, that calculation becomes unreliable — ApoB is then the better choice. LDL measures the cholesterol cargo of the particles, not the number of particles itself. ApoB does that. In people with many small, dense LDL particles, ApoB can be high while LDL appears normal. Always read LDL as part of the full lipid profile — alongside HDL, triglycerides, ApoB, and the trend across repeat measurements.

Why is LDL Cholesterol relevant?

LDL is a causal driver of atherosclerosis. The more LDL particles circulate and the longer they remain elevated, the more cholesterol deposits in the artery wall. A raised LDL causes no symptoms — the damage builds silently. That is precisely why early measurement and action matter. Lowering LDL is one of the best-evidenced preventive interventions, through both lifestyle and medication. The right target is personal: it depends on your overall cardiovascular risk, family history, ApoB, and blood pressure. Set it with a clinician — not against a single fixed cut-off.

LDL Cholesterol high or low — what it means

Read LDL alongside ApoB, HDL, triglycerides, and the trend across repeat measurements. A high LDL signals a greater atherogenic burden. Common drivers include a diet high in saturated fat, excess weight, low physical activity, and an unfavourable metabolic profile. A markedly and persistently high LDL from a young age — especially when it runs in the family — is a reason to consider an inherited tendency. The levers for lowering LDL are well established: replace saturated fat with unsaturated fat, eat more fibre, eat more plants, lose excess weight, and move regularly. Lifestyle typically shifts LDL modestly. Where risk is higher or genetics are involved, lipid-lowering medications add larger, well-proven reductions — always discussed with a clinician.

LDL Cholesterol reference ranges

Desirable (general population)About 116 mg/dL; lab-dependent reference for healthy people, not a diagnosis< 3.0 mmol/L
Target at high riskAbout 100 mg/dL; Dutch primary-care guideline (CVRM) for high cardiovascular risk< 2.6 mmol/L
Target at very high riskAbout 70 mg/dL; Dutch CVRM, e.g. with existing cardiovascular disease, typically up to age 70< 1.8 mmol/L
Strict target (specialist)About 55 mg/dL; European specialist guideline (ESC/EAS) at very high risk< 1.4 mmol/L

Cut-offs vary by lab and method. The right target is individual and depends on your overall cardiovascular risk, family history, ApoB, Lp(a), and blood pressure — set it with a clinician. 1 mmol/L is about 38.7 mg/dL.

Educational information only — not medical advice. Consult a healthcare professional for clinical decisions.

Read about our scientific approach →Read the guide: Heart health →

Frequently asked questions

What is a normal LDL cholesterol level?

For the general population, an LDL below roughly 3.0 mmol/L (about 116 mg/dL) is often used as desirable. There is no single fixed 'normal': the higher your cardiovascular risk, the lower the preferred target. At high risk the target is usually under 2.6 mmol/L (about 100 mg/dL), at very high risk (for example if you already have cardiovascular disease) under 1.8 mmol/L (about 70 mg/dL), and specialists sometimes aim under 1.4 mmol/L (about 55 mg/dL) at very high risk.

What does a high LDL mean?

A high LDL means more atherogenic cholesterol is circulating than is ideal for your risk level. LDL is a causal driver of atherosclerosis: the more LDL particles circulate and the longer they stay elevated, the more cholesterol builds up in the artery wall. It causes no symptoms itself — the damage builds silently. Common drivers include a diet high in saturated fat, excess weight, low physical activity, and genetics (familial hypercholesterolaemia).

When is a high LDL concerning?

The higher your LDL and the longer it stays elevated, the greater the atherogenic burden — so what matters most is your overall risk, not a single cut-off. An LDL above the target that fits you (under 2.6 mmol/L at high risk, under 1.8 mmol/L at very high risk) calls for action. A markedly and persistently high LDL from a young age deserves extra attention, especially when it runs in the family, as it can point to an inherited tendency. Always read LDL alongside ApoB, HDL, triglycerides, and the trend across repeat measurements, and set your target with a clinician.

Is a low LDL bad?

A low LDL is generally favourable for cardiovascular risk, and people with naturally low lifetime LDL actually have lower risk. Genuinely low values not driven down by treatment are occasionally seen with hyperthyroidism, malnutrition, malabsorption, liver disease, or acute illness, so an unexpectedly low result in someone who is unwell is worth interpreting in context.

How do I lower my LDL?

The best-evidenced levers are: replace saturated and trans fats with unsaturated fats, eat more (soluble) fibre, eat more plants, lose excess weight, exercise regularly, and don't smoke — with a Mediterranean-style pattern as a sensible default. Lifestyle typically shifts LDL modestly. Where risk is higher or genetics are involved, statins and other lipid-lowering medicines add larger, well-proven reductions, always discussed with a clinician.

Related biomarkers

Apolipoprotein B (ApoB)
ApoB is a protein on every harmful cholesterol particle, so it counts how many of those particles circulate in your blood.
HDL Cholesterol
HDL is the 'good' cholesterol that carries excess cholesterol back to your liver.
Triglycerides
Triglycerides are a blood fat that responds strongly to diet and alcohol and reflects your metabolic health.
Total Cholesterol
Total cholesterol is the sum of all the cholesterol in your blood and the starting point of the lipid profile.

LDL Cholesterol is one of the biomarkers in the Optimize blood test. Book a blood draw at any of 238+ partner labs in the Netherlands, or upload your existing results in the app.

See the full test