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Elevated cholesterol does not lead to specific symptoms unless it has been longstanding. Some types of hypercholesterolaemia lead to specific physical findings: xanthoma (thickening of tendons due to accumulation of cholesterol), xanthelasma palpabrum (yellowish patches above the eyelids) and arcus senilis (white discoloration of the iris).
Longstanding elevated hypercholesterolemia leads to accelerated atherosclerosis; this can express itself in a number of cardiovascular diseases:
If the hypercholesterolemia is hereditary, there can be a family history of premature atherosclerosis, as well as familial occurrence of the signs mentioned above.
When measuring cholesterol, it is important to measure its subfractions before drawing a conclusion on the cause of the problem. The subfractions are LDLLow-density lipoprotein LDL refers to a class and range of lipoprotein particles, varying somewhat in their size and contents, which carry cholesterol in the blood and around the body, for use by various cells. It is commonly referred to as bad cholestero, HDLHigh density lipoproteins HDL form a class of lipoproteins, varying somewhat in their size and contents, that carry cholesterol from the body's tissues to the liver. Because HDL can remove cholesterol from atheroma within arteries, and transport it back t and VLDLVery Low Density Lipoprotein (VLDL) is a lipoprotein subclass. It is assembled in the liver from cholesterol and apolipoproteins. It is converted in the bloodstream to low density lipoprotein (LDL). VLDL is prone to accelerate atherosclerosis, and is elev. LDL and VLDL levels are rarely measured directly due to cost concerns. VLDL levels are reflected in the levels of triglycerides (generally about 45% of triglycerides is composed of VLDL). LDL is usually estimated as a calculated value from the other fractions (total cholesterol minus HDL and VLDL); this method is called the Friedewald calculation; specifically: LDL ~= Total Cholesterol - HDL - (0.2 x Triglycerides).
Less expensive (and less accurate) laboratory methods and the Friedewald calculation have long been utilized because of the complexity, labor and expense of the electrophoretic methods developed in the 1970s to identify the different lipoprotein particles which transport cholesterol in the blood. As of 1980, the original methods, developed by research work in the mid-1970s cost about $5K, US 1980 dollars, per blood sample/person.
With time, more advanced laboratory analyses which have been developed which do measure LDL and VLDL particle sizes and levels, and at far lower cost. These have partly been developed and become more popular as a result of the increasing clinical trial evidence that intentionally changing cholesterol transport patterns, including to certain abnormal values compared to most adults, often has a dramatic effect on reducing, even partially reversing, the atherosclerotic process. With ongoing research and advances in laboratory methods, the prices for more sophisticated analyses have markedly decreased, to less than $100, US 2004, by some labs, and with simultaneous increases in the accuracy of measurement for some of the methods.
There is a number of secondary causes for high cholesterol: