High density lipoprotein

Lipids are carried in bloodstream in complexes with protein particles forming lipoproteins.
There are several classes of lipoproteins.
High Density Lipoprotein (HDL) is a class of blood lipoproteins.
Epidemiological studies show that high concentrations of HDL (over 60 mg%) have protective value against cardiovascular diseases (ischemic stroke, myocardial infarct etc.) and low concentrations of HDL (below 35mg%) are a positive risk factor for these diseases, especially for women.

The American Heart Association provides a set of guidelines for fasting HDL levels and risk for heart disease.

Less than 40 mg/dL

Low HDL cholesterol, hightened risk for heart disease

40 to 59 mg/dL

Medium HDL level

60 mg/dL and above

High HDL level, optimal condition considered protective against heart disease

See also: cholesterol, Low density lipoprotein.