Once past infancy, in which they are now protected from most infectious diseases, individuals are less vulnerable, increasing chances of a long life.
Public health advances during and since the nineteenth century, such as efficient sewage and water systems and the Clean Air Acts, have reduced the incidence of disease.
Houses are less damp and public buildings and workplaces are inspected for health and safety.
Dangerous and exhausting jobs such as mining and dock work have declined.
There are numerous treatments and operations that lengthen the healthy lives of older people, such as bypass operations and hip replacements.
Antibiotics and screening programmes for various cancers can tackle diseases at an early stage.
People are better informed about health, diet and exercise.