WHO/Fredrickson classification of primary hyperlipidaemias

Last reviewed 07/2021

Frederickson Classification of Lipid Disorders

Type Average of overnight serum Elevated particles Associated clinical disorders Serum TC Serum TG
I Creamy top layer Chylomicrons


Lipoprotein lipase deficiency, apolipoprotein C-II deficiency


N ++
IIa Clear LDL


Familial hypercholesterolemia, polygenic hypercholesterolemia, nephrosis, hypothyroidism, familial combined hyperlipidemia


++ N


Familial combined hyperlipidemia


++ +
III Turbid IDL




+ +
IV Turbid VLDL


Familial hypertriglyceridemia, familial combined hyperlipidemia, sporadic hypertriglyceridemia, diabetes


N+ ++
V Creamy top, turbid bottom Chylomicrons, VLDL Diabetes + ++

Note that the WHO classification is simply a biochemical phenotypic classification based on which lipoprotein is raised. Also the classification was devised before the importance of HDL as a prognostic indicator was recognised.

* IDL = intermediate-density lipoproteins; LDL = low-density lipoproteins; TC = total cholesterol; TG = triglycerides; VLDL = very low-density lipoproteins;

+ = increased; ++ = greatly increased; N= normal; N+ = normal or increased