What is Public Health? 

The American Public Health Association defines public health as “promoting and protecting the health of people and the communities where they live, learn, work and play.”

If that definition sounds broad—that’s because it is. The exciting thing about public health is that it is a diverse, expansive field, and it’s growing rapidly. Everything we do as public health professionals aims to use research and insights to encourage healthy practices, prevent disease and injury, and improve quality of life, all on a population scale. It is a critical component in the continuum of healthcare.

While doctors treat patients individually, public health sees the person as part of a bigger picture with opportunities for “treatment” beyond the individual level. We look at things like the community they live in, the food they eat and have access to, what their beliefs are, what kind of job they have, what the defining moments of their life have been—all of it matters. If this one person has been subject to a certain type of illness or injury, are there others like them? What do they have in common? As we ask more questions we often find that there are whole communities, or populations, that have similar health needs or experiences. Sometimes, it’s as simple as people who brush their teeth twice a day are less likely to get cavities than people who only brush once, but realistically, it’s almost always more complicated than that. Factors that we wouldn’t normally think of as being health-related—things like transportation, zoning, education, personal habits, and policy—can all dramatically alter a person’s ability to cultivate good health.

This means that the solutions we work to create have to be transformative. One of public health’s defining characteristics is that we are constantly trying to get ahead of the problem, approaching issues from a proactive, instead of a reactive, stance. We call this “going upstream.” Rather than treating a person after they’ve become ill or hurt, we try to prevent sickness and injury in the first place. Things like worker safety regulations, vaccination campaigns, promoting good hygiene in school or having open, honest conversations with people about the risks of unprotected sex are all examples of public health efforts that have saved lives and prevented the spread of disease.

As populations around the globe continue to grow and evolve, more public health issues are going to emerge. In order to solve them, we’ll need people of all different backgrounds and perspectives. No matter what your interests are, what you’re good at, or what you want to achieve, there’s a place where your skills and passion are needed.

For more in-depth information on specific fields in public health, please visit our department pages.

Biostatistics and Data Science


Environmental & Occupational Health Sciences

Health Promotion and Behavioral Sciences

Management, Policy and Community Health