Cholesterol ('hard bile') is the main component of the body's cell wall. 80% of cholesterol is produced in the liver, the remaining 20% is ingested with food. It prevents the cell wall from being destroyed by various aggressive factors. Another important function is participation in production of various biologically active substances - vitamin D, steroid hormones of adrenal glands, female hormones (estrogen, progesterone), testosterone. It also helps in the transmission of signals from one nerve cell to another.

The main purpose of a total cholesterol test is to diagnose atherosclerosis (and, as a consequence, coronary heart disease - CHD).

There are three types of cholesterol - high density lipoproteins (HDL), low density lipoproteins (LDL) and very low density lipoproteins (VLDL). HDL and LDL are clinically important because of their characteristics.

Low-density lipoproteins (LDL)

"Harmful" cholesterol. Its negative function is as follows: the vascular wall has a mesh-like structure. LDL penetrates these cells and gets "stuck", while HDL pass through the vascular structure and are not trapped in any way. Then, in place of the "stuck cell", inflammation occurs and an atherosclerotic plaque begins to form.

The higher the level of LDL in the blood, the greater the risk of coronary heart disease. A concentration of more than 4.14 mmol/l is considered a very high risk of developing atherosclerosis and CHD.