LDL cholesterolLDL-C · 'Bad' cholesterol
Cholesterol carried on the particles most linked to clogged arteries.
LDL cholesterol is the cholesterol carried by low density lipoprotein particles. Those particles ferry cholesterol out to the body's tissues, and when there are too many of them in circulation they lodge in artery walls and drive the plaque behind most heart attacks and many strokes.
It matters because this is not merely an association. A European Atherosclerosis Society consensus panel assessed the question against genetic studies, prospective cohorts, Mendelian randomisation and randomised trials of LDL lowering therapies, and concluded that LDL causes atherosclerotic cardiovascular disease. Very few risk factors in nutrition or cardiology are established to that standard.
The nickname bad cholesterol is a simplification worth unpicking. The cholesterol molecule is identical whichever particle carries it; what differs is the vehicle and how many of them there are. That is why ApoB, which counts atherogenic particles directly because each carries exactly one ApoB molecule, refines risk when an LDL result looks reassuring.
Cumulative exposure is the thing that does the damage, not this year's number. Arteries integrate the burden over decades, which is why a modest level held from your twenties beats an excellent level achieved at sixty, and why the genetic conditions that raise it from birth cause events so early.
Diet moves it, and how much varies a lot between people. Saturated fat intake, soluble fibre and body weight all shift it, and for some people diet alone is enough while for others it is not, which is a matter of biology rather than effort.
Read it in company. A lipid panel means more alongside blood pressure, HbA1c, family history and, ideally, one lifetime Lp(a) measurement, because these combine into risk rather than queueing up individually. Our heart age calculator uses the PREVENT equations to do exactly that combining.
Sources
- Ference BA, et al. Low-density lipoproteins cause atherosclerotic cardiovascular disease. 1. Evidence from genetic, epidemiologic, and clinical studies. A consensus statement from the European Atherosclerosis Society Consensus Panel. Eur Heart J 2017;38:2459-2472
- Khan SS, et al. Development and Validation of the American Heart Association's PREVENT Equations. Circulation 2024;149:430-449
Where your own result would sit
Most people reading this page are holding a blood-test report with this marker on it, and the question they arrived with is whether their number is normal. A reference interval says where most results from a healthy population fall; a guideline threshold is where a clinical body draws a line for a decision. Neither is a target, and a result on the wrong side of one is not a diagnosis: the same number can be unremarkable in one person and worth looking into in another, which is why the clinician who ordered the test reads it against your history rather than against a list.
LDL cholesterol has no published interval on this page yet. We hold one, and the dashboard draws it beside a reader’s own result, but it has not been read back against the laboratory’s own page since it was collected. A figure printed beside somebody’s blood result has to have been seen at its source, not remembered, so this one waits.
On your own blood test?
LDL cholesterol is one of the markers FitTools can read from an uploaded blood-test report. You confirm every value before anything is saved, and your results are explained together in one place.