LDL Cholesterol

Low-density lipoprotein cholesterol is the particle that deposits cholesterol into artery walls. Decades of randomised trials show that lowering LDL-C lowers the rate of heart attacks and strokes — the dose-response is one of the most reproduced findings in modern cardiology. Most clinical labs report LDL-C calculated from total cholesterol, HDL and triglycerides (the Friedewald equation), with direct measurement reserved for high-triglyceride states.

• Optimal: below 100 mg/dL (about 2.6 mmol/L).
• Near optimal: 100-129; borderline: 130-159; high: 160-189; very high: 190 or above.
• The right target depends on your cardiovascular risk - people at high risk aim much lower (often under 70 mg/dL), set with a doctor.

Your lab's printed range is what counts.

• Atherogenic burden — every 1 mmol/L (38.7 mg/dL) reduction lowers major vascular events by ~22%.
• Familial hypercholesterolaemia — values >190 mg/dL without lifestyle cause warrant genetic evaluation.
• Dietary pattern — saturated fat and trans fat raise LDL more than dietary cholesterol does.
• Hypothyroidism, nephrotic syndrome, cholestatic liver disease — secondary causes worth excluding.

• Usually a benign or beneficial state — very low LDL is the goal in many secondary-prevention regimens.
• Severe liver disease — impaired synthesis.
• Hyperthyroidism — accelerated clearance.
• Inflammation, malnutrition — transient drops.

• High LDL causes no symptoms - it silently contributes to artery plaque over years.
• The first sign can be a cardiovascular event, which is why LDL is screened rather than waited on.
• Very high inherited levels can occasionally show as cholesterol deposits in tendons or around the eyes.