In modern gerontology, there are three main categories of human age at the stage of late adulthood. It is possible to consider and characterize these categories from biological, social and psychological positions. The first category is called young-old and includes subjects between 65 and 74 years of age. Usually, elderly people of this age are distinguished by increased prudence, demonstrate attentiveness and rather high intellectual abilities. From a social point of view, young olds are sufficiently involved in human interactions in which they have the opportunity to demonstrate their vast knowledge and life experience. In combination with relatively good health, young-olds exhibit generally positive moods, which is why researchers call young men in the world of old age.
The second category, old-old, refers to people under the age of 85. Despite the relative independence of this social group and the opportunity to live an independent life, the number of problems in their lives, in comparison with the young-old, is strikingly increasing. Heart disease at this age is a particularly dangerous problem, and not necessarily associated with lifestyle before entering old age. Other illnesses, such as cancer or hypertension, can be prevented or reduced in risk, but the onset or intensification of chronic illnesses during this late adulthood period certainly increases.
The most growing in percentage terms in modern realities is the third group, the oldest-old, while it is assumed that with an increase in life expectancy, their number will only increase (Lally & Valentine-French, 2019). Moreover, this social group is even more susceptible to the effects of chronic diseases. Also, it is among this group that the risk of mortality and hospitalization due to cardiac arrest, urinary infection, and hip fracture is highest. In comparison with the previous two groups, the oldest-old in a much more frequent number of cases are not able to take care of themselves on their own and are forced to live in nursing homes. Within this group, there is a mini-segment of the Centenarian, that is, the elderly who have passed the age limit of one hundred years. During the previous stages of late adulthood, they show positive health indicators, which however decline sharply after the onset of 90 years.
Reference
Lally, M., & Valentine-French, S. (2019). Lifespan development: A psychological perspective. (2nd ed.). Open Education Resource.