You'll only have one lifespan. Life expectancy is also based on averages, but it's the number of years a person is expected to live from a specific starting point. Your own life expectancy changes as you age and you face different risks. Human life expectancy is the maximum number of years that an individual of the human species can live according to the examples observed.
While this definition of life expectancy may seem simple enough, it is often confused with other common concepts in the study of aging, life, and death of living organisms. The fact that the increase in life expectancy without disabilities has kept pace with the increase in life expectancy depends on the definition of disability used and on the period studied. We also need to focus on preventing and delaying disability as much as disease in order to improve health. Therefore, while the percentage increase in lifespan was substantial, the absolute increase was not large.
With the average life expectancy in the United States currently hovering around 79 years, the age at which most Americans can expect to live is still forty-four years younger than human life expectancy. Compressing morbidity or increasing relative health expectancy will require “delaying aging” or delaying the physiological change caused by illness and disability. Taking humans as an example, the oldest documented age reached by any living individual is 122 years, meaning that humans are said to have a lifespan of 122 years. In other words, the increase in HALE (5.4 years) has not kept pace with the increase in life expectancy (6.6 years).
If there is no longer any possibility of improvement in the first years of life because mortality is already very low, projections for the future based on this story would lead to an overestimation of future life expectancy. Because heart disease primarily causes death among older adults, recent increases in life expectancy have occurred at older ages. It is generally understood that closing the gap between life expectancy and life expectancy can be achieved through a healthier life, less exposure to toxins, prevention of chronic diseases, and a little luck. In terms of formulas, life expectancy is indicated by ex, where “e” represents the expected number of remaining years and “x” represents the person's current age.
This compelling idea has led to a generation of research on trends in population morbidity and healthy life expectancy. For example, a person's life expectancy is affected by personal factors such as family history, environment, diet, and even age and sex.