When we talk about too much cholesterol in the bloods we mean by that high LDL (the bad cholesterol), there is nothing called too much of a good thing; so high levels of HDL (the good cholesterol) is not considered a disease. We have to remember that the absolute values of these two lipoproteins are not that important but rather the ratio between the two. So lower than normal value of HDL, even in the presence of normal value of LDL, is still considered hypercholesterolemia.

Hereditary

Many factors can lead to having high lipid levels in the bloods like defected copy of one of the several genes that participate in lipid metabolism. The mutation might cause more production of LDL or decrease its rate of clearance from the blood. On the other hand, the mutated gene might promote faster HDL clearance or lower its production. Either way, the balance between the good cholesterol and the bad cholesterol is disturbed and there is more of the bad stuff in the blood. In such hereditary cases, a positive family history is always present, and these individuals develop arteriosclerosis earlier than usual.

Food habit

The majority of the cases are not caused by hereditary factors, but rather secondary to other conditions. Obesity is considered a risk factor because it usually indicates a certain life style with high food consumption and low physical exercises, both are incriminated in high blood lipids. High consumption of food rich in saturated fat such as found in meats, non-skim dairy products, butter and some artificially hydrogenated vegetable oils is particularly risky. We have to remember that high intake of cholesterol prevents the uptake of cholesterol circulating in the blood by the liver, and these kinds of food are not short of it.

Diabetes