Ageing is a complex process going on in an organism at all levels; it is irreversible and progressive. The consequences are agerelated structural and functional changes at the level of molecules, tissues and cells leading to involution of organs and their systems with deteriorating function. It is harder for the changed organism to keep homeostasis; it is susceptible to a failure in adaptation and compensation. Age-related changes take part in increasing diseases and specific diseases of old age. Ageing is genetic and influenced by our environment; it is individual, but also at all levels unequally and asynchronically. A diverse picture is formed not only within an organism but also within the older population which therefore is a considerably heterogeneous group. Ageing also has a psychological and social aspect, from an economic point of view it might be a reason of lowered quality of life even for a healthy senior.