Total Cholesterol

Cholesterol is a building block. Your body uses it for cell membranes, hormones and bile, and your liver makes most of it itself; what you eat supplies only a small part. Because fat does not dissolve in blood, cholesterol travels packed in lipoproteins, spheres of protein and fat, and which particle carries it decides what it does. LDL brings cholesterol to the tissues and the artery wall; HDL takes it away again and brings it back to the liver. Total cholesterol adds everything together, whichever particle it was in. Your report shows the total as one number in millimoles per litre (mmol/L). It is the cholesterol number people remember from years ago, but it is a sum that adds two opposite things together. Two people with the same total can have very different risks: one because the LDL is high, the other because the HDL is high. That is why the total says little on its own and you look at the parts. It is also why labs handle it differently: some publish what healthy people measure, by age and sex, others print a single agreed limit. The table further down shows the difference.

The total matters because most of it is cholesterol in LDL particles, and those are the cause of atherosclerosis. A high total is therefore usually a high LDL, and then everything on the LDL page applies: you feel nothing, the damage adds up over years, and lower is better. But the total can also be high because of a high HDL, and that is favourable. From the number alone you cannot tell which of the two it is. That is why nobody steers by the total any more. There is no target for it in the Netherlands; the risk estimate uses total minus HDL, non-HDL cholesterol, because that holds exactly the cholesterol that builds up in the artery wall. What remains of the total are two limits: above 5 mmol/L non-fasting blood counts as abnormal, and above 8 mmol/L a very high cholesterol counts as a severe risk factor in its own right.

A high total usually comes from a high LDL fraction, and that from what you eat, how much you weigh and what you were born with. Saturated fat from fatty meat, butter, full-fat dairy, biscuits and pastry is the biggest lever; excess weight and little exercise add to it, and how much your liver produces and clears again is partly inherited. Cholesterol in food itself, as in eggs and prawns, counts far less than people think: your liver adjusts its own production to it. Saturated fat does the opposite and sets the liver to making more LDL, which is why butter weighs more than an egg. An underactive thyroid can raise the total too. A total above 8 mmol/L, especially from a young age or with cardiovascular disease running young in the family, fits familial hypercholesterolaemia. Sometimes a high total comes from a high HDL, and then nothing is wrong. A low total is usually simply healthy: anyone who eats plant-based and fibre-rich, is lean and exercises often has a low LDL and so a low total. Sometimes it is cholesterol-lowering medication, and sometimes a low HDL, which is a different situation. You bring it down through the LDL. Olive oil instead of butter, nuts and oily fish instead of fatty meat and processed meat, more fibre from oats, legumes, vegetables and fruit, losing weight if you carry too much and moving every day. For most people without an inherited condition that is enough, and you see it back in your blood within weeks to months. With an inherited high cholesterol or existing cardiovascular disease, lifestyle remains the foundation and medication usually joins it. Always look at the parts: LDL and non-HDL say what ends up in the artery wall, HDL and triglycerides show the metabolic pattern. And read the total as a trend: one measurement is a snapshot.