Total Cholesterol / HDL Ratio

What it is

This is your total cholesterol divided by your HDL, printed on many panels as a single convenience number. It compresses two values into one, which is its appeal and its weakness: the same ratio can come from very different lipid pictures — modest total cholesterol with low HDL, or high total cholesterol with high HDL — and those are not the same situation. It also inherits any uncertainty in its inputs. Contemporary risk assessment tends to work from the components and from non-HDL cholesterol or apolipoprotein B, which count the cholesterol-carrying particles more directly. Treat the ratio as a quick orientation to the panel rather than the number to act on, and read the individual values underneath it.

Worth asking your clinician

• Do you use the cholesterol/HDL ratio, or do you prefer to look at the individual values?