The life expectancy in the United States blossomed in less than 100 years. It bloomed from a paltry 50 years to nearly 80 years from 1900 to 2000. Before that, life expectancy hovered at around 35 for the average human due to harsh living conditions and lack of medical attention and education. A number of factors played into extending the life expectancy of Americans in such a short period of time. From science to society, exciting changes and discoveries brought health and wellness to most Americans and are the main reasons why life expectancy has increased.

Advances in Medical Care

Infectious diseases took a beating in the middle of the 20th century. Taking precautions in sanitation during medical visits and during outbreaks of contagious diseases and viruses and generally cleaner living conditions greatly contributed to extending life expectancy. With education about how germs spread and laws about clean water, adults and children were getting sick less often and were not as easily spreading colds, flus and other debilitating illnesses. Living conditions became more sanitary.

The main causes of death in 1900, which were pneumonia, dysentery, enteritis, diphtheria and tuberculosis, were confronted and controlled by the middle of the century. The creation of penicillin in the early 1940s took down bacterial infections and beat back the death rate. Typhoid fever was rampant in the damp and water-logged areas of the poorer sections of town. Sewage lines were installed and maintained along with clean, free water lines, which allowed people to wash their hands regularly and to rid their homes and alleys of waste.

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What Has Led to Improvement in Life Expectancy?

Microbes were the main culprits in reducing life expectancy. These included bacteria, amoebas, viruses and protozoans, particularly in areas prone to flooding and damp conditions. Cleaning up living conditions eradicated many of these issues by the mid part of the last century. This significantly led to the improvement in life expectancy.

Vaccinations became a lifesaver for millions of people who partook of this serious medical advancement. They practically eliminated smallpox, measles, mumps, tetanus, diphtheria, rubella, scarlet fever and Type B meningitis. A combined vaccine of tetanus, pertussis and diphtheria in 1949 that had state and federal health department backing quickly eradicated those issues for the majority of the population. This success led to increased value in vaccines for the general public.

The Salk polio virus vaccine brought federal funding to the vaccine issue in 1955. This led to childhood vaccination programs in the early 1960s that significantly increased a generation’s life expectancy by more than 20 years. The 1962 Vaccination Assistance Act supports a full range of childhood vaccines to be made mandatory for school-aged children unless otherwise requested by the parents or guardian of the child.

Technology Raises a Hand

Education and technology played a large part in the causes of longevity. The ability to diagnose and treat patients quickly through technology, equipment and the sharing of information added much to the increased life expectancy of Americans.

Blood testing began to make its way into medical institutions in the early 1900s, becoming an accredited way to more precisely diagnose disease-causing bacteria and to treat the patient quickly and accurately. The advances in serologic testing spread to small medical facilities as the process advanced and became easier to complete.

X-ray technology evolved into MRI technology, which could detect cancers and abnormalities in soft tissues, kidneys, ovaries or other major organs. This significantly advanced the life expectancy of the average American, halting debilitating diseases before they could silently and invisibly take hold of a patient. Computers have played a big part in the improvement in life expectancy, from sharing information to numerous physicians working on a single patient to using sound and light to give more distinct imaging of tissues, organs and bones.

About the Author

Kimberley McGee is an award-winning journalist with 20+ years of experience writing about education, jobs, business trends and more for The New York Times, Las Vegas Review-Journal, Today’s Parent and other publications. She graduated with a B.A. in Journalism from UNLV. Her full bio and clips can be seen at