The standard lipid panel is the blood test I’m asked about more than any other — and the one most often misread. Here is how I actually read one, line by line, and the single number worth adding to it.
Total cholesterol
This is the sum of the cholesterol carried in all your lipoprotein particles. It was the first cholesterol measurement we ever used, and it’s the least useful one on the panel. A “normal” total cholesterol can hide a real problem, and a high one is often driven by a high HDL, which isn’t harmful. I rarely make a decision on total cholesterol alone.
LDL cholesterol (LDL-C)
The cholesterol carried inside your LDL particles — the particles that drive atherosclerosis. Most treatment decisions still hang on this number, and for most people it tracks risk reasonably well. Two caveats worth knowing: on a standard panel LDL-C is usually calculated, not measured, and the calculation becomes unreliable when triglycerides are high. And it tells you the cholesterol inside the particles, not the number of particles — which is what actually matters.
HDL cholesterol (HDL-C)
Labelled the “good” cholesterol, but the story is more complicated than that. A higher HDL-C tracks with lower risk across populations, yet raising it with drugs has never lowered heart attacks or strokes — so I don’t treat HDL as a target. A very low HDL-C is still useful information: it often points to insulin resistance or a metabolic problem worth addressing.
Triglycerides
A type of fat carried mainly in VLDL particles, best measured after an 8-hour fast. High triglycerides are rarely the direct cause of a heart attack, but they’re a useful flag — usually for insulin resistance, too much alcohol, or too much refined carbohydrate. The good news is that they respond well to lifestyle change.
The ratios
The total-cholesterol-to-HDL ratio and the triglyceride-to-HDL ratio get used as quick markers of risk and of insulin resistance. They’re better than total cholesterol alone, but they’re a workaround. If you can get the real numbers, use those instead.
The number that’s usually missing: ApoB
Here’s what the standard panel leaves out. Every atherogenic particle — LDL, VLDL, IDL and Lp(a) — carries exactly one ApoB protein. So ApoB counts those particles directly, and particle number predicts risk better than the cholesterol they carry. If you can add one test to your panel, make it ApoB. If you can’t, non-HDL cholesterol (total minus HDL) is a free, decent stand-in that’s already sitting in your results.
What I’d ask for: a standard panel plus a directly-measured LDL-C, an ApoB, and — once in your life — a lipoprotein(a). That gives you a far clearer picture than the basic four numbers.
This is general information, not medical advice. Use it as a starting point for a conversation with your own doctor.
Dr Mike MacDonald
Consultant cardiologist in Singapore writing about preventive cardiology, lipid management and longevity medicine.
