Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is a form of "hyperlipidemia" and "hyperlipoproteinemia". Cholesterol is a sterol, a sort of fat; see the diagrammatic structure at the right. It is one of three major classes of lipids which all animal cells utilize to construct their membranes and is thus manufactured by all animal cells. Plant cells do not manufacture cholesterol. It is also the precursor of the steroid hormones, bile acids and vitamin D. Since cholesterol is insoluble in water, it is transported in the blood plasma within protein particles. Lipoproteins are classified by their density: very low density lipoprotein, intermediate density lipoprotein, low density lipoprotein and high density lipoprotein. All the lipoproteins carry cholesterol, but elevated levels of the lipoproteins other than HDL, particularly LDL-cholesterol are associated with an increased risk of atherosclerosis and coronary heart disease. In contrast higher levels of HDL cholesterol are protective. Elevated levels of non-HDL cholesterol and LDL in the blood may be a consequence of diet, obesity, inherited diseases, or the presence of other diseases such as diabetes and an underactive thyroid. Wikipedia [ - ]

Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is a form of... [ + ]