What is a normal LDL cholesterol level?

For most adults, an LDL level below 3.0 mmol/L (116 mg/dL) is considered acceptable. For people with diabetes, heart disease, or high cardiovascular risk, the target is typically below 1.8 mmol/L (70 mg/dL). Your doctor will interpret your result in the context of your overall risk profile.

What is the cholesterol ratio and why does it matter?

The total cholesterol to HDL ratio (TC:HDL) is calculated by dividing total cholesterol by HDL. A ratio below 4.0 is generally considered healthy. A lower ratio indicates proportionally more protective HDL relative to total cholesterol, which is associated with lower cardiovascular risk.

What is the difference between LDL and HDL cholesterol?

LDL (low-density lipoprotein) carries cholesterol to the arteries and, in excess, contributes to plaque build-up. HDL (high-density lipoprotein) transports cholesterol away from the arteries back to the liver for removal. High HDL is protective; high LDL increases cardiovascular risk.

Do I need to fast before a cholesterol blood test?

Fasting for 9 to 12 hours is traditionally recommended for a full lipid panel, as triglycerides are most accurately measured in a fasted state. However, many guidelines now accept non-fasting tests for initial screening. Your doctor or lab will specify which is required.

What happens if my LDL is high?

If LDL is mildly elevated, your doctor will typically recommend lifestyle changes first: reducing saturated fat, increasing soluble fibre, and increasing physical activity. If LDL remains elevated or cardiovascular risk is high, statin medication may be prescribed. Repeat testing is usually done 3 to 6 months after intervention.

Understanding Your LDL and Cholesterol Ratio Results

Quick answer: LDL (“bad”) cholesterol should be below 3.0 mmol/L for most adults, and below 1.8 mmol/L if you have diabetes or heart disease. HDL (“good”) cholesterol should be above 1.0 mmol/L (men) or 1.2 mmol/L (women). Your total cholesterol to HDL ratio should be below 4.0. A single number means little — your doctor will assess your full cardiovascular risk profile.

A lipid panel (cholesterol blood test) gives you four numbers: total cholesterol, LDL, HDL, and triglycerides. Understanding what each means — and how they interact — helps you have a more informed conversation with your doctor and understand why treatment may or may not be recommended.

This guide explains each value, the reference ranges used across Singapore, Australia, and the US, and what your doctor will likely discuss based on your result.

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The Four Numbers on Your Cholesterol Report

Total Cholesterol (TC): The sum of all cholesterol in your blood. A useful screening figure but not the most important number on its own.

LDL — Low-Density Lipoprotein (“bad” cholesterol): LDL carries cholesterol to the arterial walls. Chronically elevated LDL contributes to atherosclerosis (plaque build-up), which raises the risk of heart attack and stroke. This is the primary treatment target in cardiovascular prevention.

HDL — High-Density Lipoprotein (“good” cholesterol): HDL transports cholesterol away from the arteries back to the liver. Higher HDL is protective. Low HDL (below 1.0 mmol/L in men, 1.2 mmol/L in women) is an independent cardiovascular risk factor.

Triglycerides: A type of fat in the blood, elevated by high sugar and refined carbohydrate intake, excess alcohol, obesity, and uncontrolled diabetes. High triglycerides (above 1.7 mmol/L) alongside low HDL is a pattern associated with metabolic syndrome.

Normal Ranges: What the Numbers Mean

Reference ranges below are in mmol/L (standard in SG, AU, UK) with mg/dL equivalents for US patients.

Marker	Optimal	Borderline High	High / Concern
Total Cholesterol	Below 5.0 mmol/L (193 mg/dL)	5.0–6.2 mmol/L	Above 6.2 mmol/L (240 mg/dL)
LDL	Below 3.0 mmol/L (116 mg/dL) Below 1.8 if high risk	3.0–4.9 mmol/L	Above 4.9 mmol/L (190 mg/dL)
HDL (Men)	Above 1.0 mmol/L (40 mg/dL)	—	Below 1.0 mmol/L = risk factor
HDL (Women)	Above 1.2 mmol/L (46 mg/dL)	—	Below 1.2 mmol/L = risk factor
Triglycerides	Below 1.7 mmol/L (150 mg/dL)	1.7–5.6 mmol/L	Above 5.6 mmol/L (500 mg/dL)
TC:HDL Ratio	Below 4.0	4.0–5.0	Above 5.0

What Is the Cholesterol Ratio and Why Do Doctors Use It?

The total cholesterol to HDL ratio (TC:HDL) is calculated simply: divide your total cholesterol by your HDL. For example, total cholesterol 5.2 mmol/L ÷ HDL 1.3 mmol/L = ratio of 4.0.

The ratio is useful because it accounts for protective HDL. Two patients can have the same total cholesterol of 5.5 mmol/L, but very different risk profiles if one has HDL of 1.8 and the other has HDL of 0.9. The ratio captures this difference. Many cardiovascular risk calculators (used in SG, AU, and UK) incorporate the TC:HDL ratio rather than LDL alone.

What Will Your Doctor Do with These Results?

An elevated cholesterol result does not automatically mean medication. Your doctor will assess your 10-year cardiovascular risk score — a calculation that includes age, sex, blood pressure, smoking status, diabetes, and cholesterol values. Treatment recommendations depend on this overall risk, not the cholesterol number in isolation.

Low overall risk + mildly elevated LDL: Lifestyle intervention first — reduce saturated fat, increase soluble fibre (oats, legumes, vegetables), exercise 150 minutes/week, reduce alcohol and refined carbohydrates. Repeat test in 3–6 months.
Moderate risk or persistently elevated LDL: Statin therapy may be introduced (atorvastatin, rosuvastatin, simvastatin). Statins reduce LDL by 30–50%.
High risk (existing heart disease, diabetes, prior stroke): Target LDL is typically below 1.8 mmol/L (70 mg/dL). Statin therapy plus dietary changes is standard.

Keeping a health tracking journal is useful for logging dietary changes and noting how your results change at each repeat test — this helps you see the impact of lifestyle modifications clearly.

Questions to Ask Your Doctor

Based on my full cardiovascular risk profile, does this result require treatment or lifestyle changes first?
What is my TC:HDL ratio, and is it within a healthy range?
If you are recommending a statin, which one and at what dose — and what should I watch for in terms of side effects (muscle aches, liver function)?
How long do lifestyle changes typically take to show up in repeat tests?
Should I be tested for familial hypercholesterolaemia (inherited high cholesterol)?

Fasting vs Non-Fasting Tests

Traditionally, a 9–12 hour fast before a lipid panel was required because triglyceride levels are affected by recent food intake. However, many current guidelines (including the European Atherosclerosis Society) now accept non-fasting tests for initial LDL screening, as LDL values are minimally affected by food. Your lab or doctor will specify which is required for your test. If fasting is required, water is permitted.

Regional Context

Singapore: MOH clinical guidelines use a 10-year Framingham risk score. Statins are on the Chronic Disease Management Programme (CDMP) subsidy list — patients with hyperlipidaemia can claim Medisave for CDMP-registered GP visits and medication.

Australia: The Australian Cardiovascular Risk Calculator is used. PBS-subsidised statins are available with a prescription. Rosuvastatin and atorvastatin are both on the PBS.

United States: ACC/AHA guidelines use a Pooled Cohort Equations risk calculator. The LDL target for high-risk patients is below 70 mg/dL (1.8 mmol/L). Generic statins are widely covered under most insurance plans.

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Medical Disclaimer: This guide is for informational and preparation purposes only. It does not constitute medical advice, diagnosis, or treatment. Cholesterol targets vary by individual risk profile. Always consult a qualified medical professional before starting, stopping, or changing any medication or treatment.