In spite of the tireless pursuit of “Eternal Youth”, the process of biological aging of people is, until now, irreversible, and starts practically from birth. The aging of the population is usually expressed by the increase in the proportion of older people and is influenced by such factors as the reduction of fertility and mortality, although migrations, for example, can also contribute. The increase in the number of elderly people demands new questions related to themselves and their repercussion in educational, economic, social, health, environmental, recreational and generational aspects, among others.

In Latin America and the Caribbean, the number of people aged 60 and over will increase steadily in the coming decades. Between 2000 and 2025, 57 million older people will join the existing 41 million and between 2025 and 2050 that increase will be 86 million people. It is a fast growing population (3.5%) and with a greater impetus than the population of younger ages. The rate of change of this population will be between three and five times greater than that of the total population in the periods 2000-2025 and 2025-2050, respectively (1). The United Nations has affirmed that this is a silent revolution that, due to the unprecedented speed and the context of inequality in which it occurs, will have serious consequences for development, public policies and human rights.

In Paraguay, the process of aging has been visible for a couple of years due to the growth of this population. Currently, this population group is composed of almost 700 thousand people, 10.4% of the total population (2), and an 18% weight of older adults is projected in the whole population around 2050 (3).

The concept of health has been a very controversial aspect of medicine over time. The criterion that health is equal to the absence of disease has been deprecated, and WHO introduced the concept that health is "a state of complete physical, mental and social well-being and not only the absence of affections and diseases". Health is a state of equilibrium, with a certain degree of subjective components, between the biological and the psychical states with the social, cultural and natural environment (4). It is obvious that the WHO criterion for defining health does not apply to the elderly. The changes that accompany the process of aging cause certain functional deficiencies in organs of the body that lead to the functional diminution of the organism as a whole.

Aging is associated with an increase in the incidence of various chronic diseases, including coronary artery disease, type II diabetes, and osteoporosis. It is well documented that, in addition, there are changes in body composition that include increases in body fat and a progressive decline in muscle mass and bone density, factors that together result in a decrease in muscle strength and aerobic capacity (5).

Among the most important conditions which cause morbidity and mortality in the elderly, there are the cardiovascular diseases. The Framingham study and other similar studies have established the role of hypertension in cardiovascular mortality, especially after age 60. This is a serious health problem because it is also an important risk for the development of other diseases, such as: atherosclerotic conditions, ischemic heart disease, stroke and renal failure. In the geriatric patient, the presence of hypertension increases the risk of cardiovascular death threefold (6).

In addition, these diseases that affect the physical health of the elderly combined with the physical deterioration of age have consequences on mental health generating negative emotions such as sadness, anxiety, loneliness and low self-esteem, which in turn lead to social isolation and apathy. Another more serious consequence is depression, which in turn has physical and mental consequences that can complicate an existing health problem of an elderly person and trigger new concerns (7). The theme of the World Health Day 2017 campaign is depression, and WHO reminds us not only that it can be prevented and treated, but that there is a lot of work to be done on this area, especially in older adults (8).

The maximum duration of human life has not been established so far, although some scientists estimate it in about 120 years, but the important thing is not to reach this age, or even prolong the existence, but to be able to live years free of disabilities, a healthy aging, so that we are active subjects to the limit of our lives (9).

The WHO defines active aging as the process of optimizing opportunities to fight for health, for an active participation in life, and for the security of achieving quality of life when the human being grows old. By maintaining healthy, functional and independent older adults, they can contribute wisdom and experience to their communities and families, and lead a more dignified, less solitary and happier life.