Old age refers to ages nearing or surpassing the life expectancy of human beings, and is thus the end of the human life cycle. Terms and euphemisms for people at this age include old people, the elderly (worldwide usage), OAPs (British usage which stands for Old Age Pensioner), seniors (American usage), senior citizens (American usage), older adults (in the social sciences^[1]), and the elders (in many cultures).

Elderly people often have limited regenerative abilities and are more susceptible to disease, syndromes, injuries, and sickness than younger adults