Learn about NIA, one of the Institutes of NIH, which leads the federal government in research on aging and Alzheimer’s disease and related dementias. Aging is a gradual, continuous process of natural change that begins in early adulthood. During early middle age, many bodily functions begin to gradually decline. People do not become "older" or "elderly" at any specific age. Traditionally, age 65 has been designated as the beginning of older age. But the reason was based in history, not biology. AGING definition: 1. US spelling of ageing 2. relating to getting older: 3. used to describe a person or thing that…. Learn more. Ageing is the process during which structural and functional changes accumulate in an organism as a result of the passage of time. The changes manifest as a decline from the organism’s peak ...
