A more practical system categorizes dyslipidemias as primary or secondary and characterizes them by Increases in cholesterol only: Pure or isolated hypercholesterolemia Increases in TGs only: Pure or isolated hypertriglyceridemia Increases in both cholesterol and TGs: Mixed or combined hyperlipidemias This system does not take into account specific lipoprotein abnormalities (eg, low HDL-C or high LDL-C) that may contribute to disease despite normal cholesterol and TG levels.