Total cholesterol

Total cholesterol is the combined amount of cholesterol carried across all the lipoprotein particles in your blood — chiefly LDL and HDL. Cholesterol itself is an essential fatty substance the body uses to build cell membranes and hormones.

It matters as a quick headline number, but on its own it can mislead: a high total can be driven by protective HDL, and a reassuring total can hide an unfavourable balance. The split between the types, and the particle number, matter far more than the sum.

In practice, total cholesterol is always read together with HDL, LDL and triglycerides, and increasingly with ApoB, to judge cardiovascular risk properly rather than from the total alone.