Later years of life. The causes of progressive degeneration of bodily and mental processes associated with it are still not precisely known, but every one of the phenomena of aging can occur at almost any age, and the process does not take place throughout the body at an equal rate. Geriatrics is the branch of medicine dealing with the diagnosis and treatment of disease in the elderly.
Normally, aging begins after about 30. The arteries start to lose their elasticity, so that a greater strain is placed on the heart. The resulting gradual impairment of the blood supply is responsible for many of the changes, but between 30 and 60 there is a period of maturity in which aging usually makes little progress. Research into the process of aging (gerontology) includes study of dietary factors and the mechanisms behind structural changes in the tissues. Old age in itself is not a disease.
Time of life; SYN. years, age.