Old age can be defined as a variety of changes in structure and function which begin at the stage of reproductive maturity, and that changes are manifested as a lesser ability of adaptation and lesser way of defending from the influence of outside and inside factors. Neurons of sympathetic trunk, as well as the other neuron cells, are changeable during the life. Neurobiological, old age begins at the time of birth, because the number of neurons is not increasing, it's only getting lower, which means that neurons are post mitotic cells. The process of old age is increased with some degenerative changes at some diseases and its hard to know what belongs to, so called, physiologic way of getting old and what is pathologic. Concentration of lipofuscin in cells (pigment of old age), is the parameter for physiologic old age of a person. Concentration is changeable, and it depends from the tissue or the organ, concentration is controlled by the internal regulatory factors and the factors of environment as the way of nutrition, physical activity, stress and hygienic factors.