Old is a stage where a person gradually experiencing changes in physical functionalities such as blurred vision, hearing impairment, tastelessness, weak joints, saggy skin, grey hair or balding, slow reflects, hobbling, loosen teeth, weakened immune system, weakened muscle, high blood pressure, high cholesterol, heart attack. 


Some people also experiencing deterioration of mental capacity, for example dementia, slow responses, failing memory, after-effects of stroke. These signs usually manifest around the age of 65. Some people are earlier, some are later.

In sociology terms, the older adult population are divided into 3 life-stage subgroups:

If we refer to the generation groups below (Figure 1), the young-old now and 10 years later are under the Baby Boomers, middle-old and old-old are those in Builders and WW II era. In 20 years’ time (2041), people who are now 41–56 (Generation X) will be the new young-old cohort.

Figure 1: Generation groups by years and ages

Of course, given the advancement in medical technologies, it will extend the longevity span further, and the age group for young-old today may not be the same 20 years later.