As people age, their bodies become more susceptible to various ailments. For some, this would be the result of earlier diseases or other physical conditions. For others, it is likely due to wear and tear as both internal and external organs lose their flexibility, resilience, and recuperation capabilities, resulting in generally poorer health.
However, for increasingly larger numbers of people, it appears that many old-age ailments are the end outcomes of long periods of various constant major or minor abuses, which may be physical, mental, environmental, dietary, or various combinations of all four factors. This may simply be due to living in a modern world packed with unhealthy foods, drinks, stress, and environmental hazards.