blood high density lipoprotein cholesterol level CMO:0000052 EFO:0004612 EFO:0007805 EFO:0022157 HDL cholesterol change measurement Measurement of the amount of cholesterol, a eukaryotic sterol that in higher animals is the precursor of bile acids and steroid hormones and a key constituent of cell membranes, carried in high-density lipoprotein (HDL) molecules in a specified volume of blood, the fluid that circulates through the heart, arteries, capillaries and veins carrying nutrients and oxygen to the body tissues and metabolites away from them. HDL is the smallest of the major lipoprotein particles, complex molecules that consist of a protein membrane surrounding a core of lipids. The HDL class of lipoproteins, specifically the subtypes of HDL2 and HDL3, have densities between 1.063 and 1.210 g/ml. VT:0000184 Values for density ranges of the lipoprotein classes are approximate. The classes may be defined differently by different researchers, in part because class definitions depend on the number of subclasses into which the lipoprotein fractions are divided. blood HDL level blood HDL-C clinical_measurement_ontology free cholesterol in large HDL measurement high density lipoprotein cholesterol measurement blood lipoprotein cholesterol level