A quality of life of elderly patients depends more on ageing-related disease than solely on chronological characteristics. ‘Natural’ transformations in the status of the organism during the process of ageing, such as the changes in the immune, cardiovascular and endocrine systems (Martin, & Sheaff 2007), occur simultaneously with abnormal pathological processes associated with variety of age-related diseases, such as wear and tear of skin, muscles, and skeleton (Freemon, & Hoyland 2007), cardiovascular system (Greenwald 2007), etc. These two types of changes interact closely in various types of age-related diseases such as hearing loss, noise damage, skin damage, hypertension, increased body mass index, etc.
The process of aging is associated with changes in the human brain at the macroscopic and microscopic levels. Although the recent studies have found that loss of neurons in aging persons is more modest than many past studies suggested and is limited to only some neuron populations, the reduction in the size of remaining neurons has been revealed as well as a reduced size of dendritic and axonal arborizations (Esiri 2007). Electrical activities of the brain change notably as the personal growth older. The changes are observed primarily in a rhythm of the brain and they do not depend on the absence or presence of any physical disorders or diseases.
Serious cognitive changes are associated with aging. Various cognitive abilities demonstrate different patterns of change over the process of normal aging. (Schaie, 1994). The most common changes occur to reaction time, the overall speed of information processing, and reduction in visuospatial and motor control abilities, memory, and attention, particularly the ability to divide one's attention, to shift focus rapidly, and to deal with complex situations (APA, 2003). Cognitive functions that are better preserved with age include learning, language and vocabulary skills, reasoning, and other skills that rely primarily on