Old age refers to ages nearing or surpassing the life expectancy of human beings, and is thus the end of the human life cycle. In October 2016, a highly publicized paper  claimed the maximum human lifespan is an average age of 115, with an absolute upper limit of 125 years, but the authors' methods and conclusions are controversial. Terms and euphemisms for old people include, old people (worldwide usage), seniors (American usage), senior citizens (British and American usage), older adults (in the social sciences), the elderly, and elders (in many cultures—including the cultures of aboriginal people).
Old people often have limited regenerative abilities and are more susceptible to disease, syndromes, and sickness than younger adults. The organic process of ageing is called senescence, the medical study of the aging process is called gerontology, and the study of diseases that afflict the elderly is called geriatrics. The elderly also face other social issues around retirement, loneliness, and ageism.United Nations proposed a human rights convention that would specifically protect older persons.