Public health is a field within healthcare that focuses on the science and medical practice behind preventing and containing injury and illness in a population. This sector is responsible for the global eradication of smallpox, a disease that killed an estimated 300 million people in the 20th century alone. Today, public health professionals continue to seek cures for cancers and diseases, including HIV/AIDS, breast cancer, and diabetes. They also work to improve the overall health of communities through research, regulation, education, and high-quality, accessible health care.

As the world population increases, so does the number of people entering and exiting the United States — in 2013, the U.S. received 69.8 million visitors; 29 million U.S. residents travelled overseas. This, in turn, means the work of public health employees is needed more than ever to keep communities safe. Learn more about the different areas of public health working at the local, national, and international level.

Areas Within Public Health

  • Communications

    Hands-Only CPR, a technique to use on someone suffering from cardiac arrest until paramedics arrive, has been found to be more effective at saving lives than traditional CPR. In 2009, the American Heart Association promoted a PSA advocating this technique which increased public awareness from 56% to 63% and reported willingness to perform from 39% to 44%.

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  • Emergency Management

    The Strategic National Stockpile (SNS) is a national repository of medical countermeasures, vaccines, and supplies, which are designed to supplement state and local public health departments in the event of a large-scale public health emergency. This can help provide emergency medicines to protect the U.S. against threats for under $2 per person annually.

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  • Environmental Health

    1 in 8 total global deaths is a result of air pollution exposure, with 7 million deaths in 2012 alone. In fact, air pollution from the burning of fossil fuels is the world's largest environmental health risk, emphasizing the need for more pollution regulation in the U.S. and abroad.

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  • Epidemiology & Research

    Breast cancer mortality has declined by 24% over the past decade, thanks to advances in detection and screening. Research found that a prior family history of certain types of other cancers (such as skin cancer) could indicate a higher risk of breast cancer as well. This discovery changed the factors that went into evaluating an individual's breast cancer risk.

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  • Medical Practice

    The flu vaccination is not a complete safeguard against catching influenza, but it reduced the vaccinated population's risk of having to go to the doctor because of influenza by 60% in the 2013-14 flu season.

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  • Mental Health

    Depression affects about 9.5% of American adults, and mood disorders (including depression) are the third leading cause of hospitalization in the U.S. But in recent years, an increased awareness of mental health issues has resulted in more people seeking treatment than ever before.

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  • Public Health Education

    In 2011, the CDC awarded $55 million to 34 community organizations to expand their HIV prevention services and education programs to minority youths, who accounted for 79.7% of all new HIV diagnoses among those aged 13-24 years.

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  • Public Policy & Administration

    A policy enacted by the World Health Assembly, the Polio Eradication and Endgame Strategic Plan aims to eliminate all cases of polio worldwide by 2018 through mandatory vaccination and tracking. As a result, the number of polio cases globally has declined more than 99% from the plan's initial enactment in 1988 to 2012.

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Health Guides


Whether you are practicing public health professional or still a student, use our resources to find online journals publishing high-impact research, free course materials from top universities, and information on professional organizations and studies.

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