Understanding Your Cholesterol: Good vs Bad Cholesterol
By Dr Nabila Laskar — published February 2025.
Breaking down HDL, LDL, triglycerides and what your numbers really mean for your heart health.
What is Cholesterol?
Cholesterol is a waxy, fat-like substance essential for building cells, producing hormones and making vitamin D. The liver produces all the cholesterol your body needs; you also get some from animal-based foods. The problem isn't cholesterol itself — it's having too much of certain types in your bloodstream. High cholesterol is a major risk factor for heart disease and stroke and has no symptoms, so blood testing is crucial.
HDL, LDL and Triglycerides
HDL (good cholesterol) acts like a cleanup crew, taking excess cholesterol back to the liver. Optimal: men >1.0 mmol/L, women >1.2 mmol/L. LDL (bad cholesterol) deposits cholesterol in artery walls, forming plaque (atherosclerosis). Targets: <3.0 mmol/L low risk; <2.6 moderate risk; <1.8 high risk. Triglycerides are blood fats stored from excess calories (especially sugar and alcohol). Target: <1.7 mmol/L.
Understanding Your Cholesterol Report
Total cholesterol alone doesn't tell the full story — what matters more is the ratio between cholesterol types and your overall cardiovascular risk. Key ratios: Total Cholesterol/HDL should be below 4.5; Non-HDL Cholesterol (total minus HDL) includes all harmful particles; Apolipoprotein B (ApoB) is an advanced marker that counts actual harmful particles more accurately than LDL alone.
When Do You Need Treatment?
The decision to treat is based on overall cardiovascular risk, not numbers alone. Non-modifiable factors include age, family history of early heart disease, South Asian ethnicity, and personal history of heart disease or stroke. Modifiable factors include high LDL, low HDL, high blood pressure, diabetes or prediabetes, smoking, and abdominal obesity.
Lifestyle Strategies
Reduce saturated fat (red meat, butter, full-fat dairy), eliminate trans fats (processed foods, fried fast food), increase soluble fibre (oats, beans, lentils, vegetables), eat omega-3 oily fish 2–3 times weekly, and choose plant sterols. Regular aerobic exercise (150 minutes weekly) raises HDL and lowers triglycerides. Losing 5–10% of body weight significantly improves triglycerides and HDL.
Medication: Statins and Beyond
If lifestyle changes aren't enough — or your cardiovascular risk is high — medication may be recommended. Statins are the most prescribed and well-researched cholesterol medications. Side effects like muscle aches occur in 5–10% of people; for most people at high risk the benefits far outweigh the risks. Alternatives include ezetimibe, PCSK9 inhibitors and bempedoic acid.