Total cholesterol is the sum of all cholesterol measured in a person's blood. This total includes high-density lipoprotein (HDL), which is sometimes called the "good cholesterol," and low-density lipoprotein (LDL), sometimes called the "bad cholesterol," and very low-density lipoprotein (VLDL).

Cholesterol is measured either in millimoles per litre of blood (mmol/L) or in milligrams per decilitre of blood (mg/dL).

The ratio of total cholesterol to "good" (HDL) cholesterol is also important, especially if total cholesterol is high.