The progressive aging of the population worldwide due to the increase in life expectancy has led to an increasing number of people over 70 years of age. It is called frail old man to one who is at risk of disability. Age does not determine the presence of frailty, a 70-year-old person may be a frail old man and, however, a 90-year-old person may not be.

This entity is associated with aging due to the loss of functional reserve and muscle mass, which predisposes to loss of function and autonomy, rather than the existence of chronic diseases. A patient may suffer from chronic diseases, but would fall within the frail elderly group when there is a loss of functional reserve that makes him vulnerable to stressful situations, with a greater risk of serious health problems such as major disability, hospitalization, institutionalization or even death in those cases in which serious complications appear. This loss of function is what decreases the quality of life because it translates into a loss of autonomy.