The paper describes the important biological role of reactive oxygen radicals which are generated in various cells of able-bodied organisms from unicellular up to high-organized organisms. Due to a highest chemical reactivity and rather short lifetime vital function they carries out alarm endocellular messengers and intercellular mediators for realization of the expedited and deferred adaptable rearrangement of a metabolism in tissues, including system of a blood circulation. At the same time at appreciable accumulation of such molecules in an organism their mediator function is transformed into damaging function caused by oxidation and destruction of histic lipids, proteins and nucleic acids with development of pathological damages of organs and tissues.

Key words: cardiovascular diseases, risk factors, free-radical oxidation, dislipoproteinemies.