Epidemiologists and medical scientists are public health workers who study diseases and illnesses, their causes and what can be done to reduce their occurrence. Depending on their specialty and career path, epidemiologists can be found working at federal agencies, state and county health departments, hospitals, universities and other research institutions.

“The thing about epidemiology is it’s a career that can go in many different directions,” says Dale Sandler, chief of the epidemiology branch at the National Institute of Environmental Health Sciences, a part of the National Institutes of Health based in North Carolina’s Research Triangle Park. “There are epidemiologists who work in hospitals and in infection control. And there are people who work at the CDC who work in the really exciting area of trying to track down outbreaks of infectious or noninfectious illnesses, and they’re out in the field doing vaccine development, eradicating diseases.”

Sandler is a research epidemiologist who studies chronic diseases, trying to understand the causes behind why some people are susceptible to certain diseases while others are not.

“I design these really large cohort studies where we enroll people and follow them over time and can ask a lot of questions,” she says. “In one of these studies, for example, we’re interested in why some women are more at risk for breast cancer than other women.”

The Bureau of Labor Statistics projects 26.7% employment growth for epidemiologists or medical scientists between 2022 and 2032. In that period, an estimated 2,700 jobs should open up.

Epidemiologists usually need at least a master’s degree in a relevant field. Although no specific major is required to become an epidemiologist, the BLS says a master’s degree in public health with an emphasis in epidemiology is common. Those who orchestrate research projects usually have a doctoral degree; Sandler, for example, has a Ph.D. in epidemiology.

“Epidemiology programs include coursework in public health, biological and physical sciences, and math and statistics,” according to the BLS. “Topics of study may include comparative health care systems, medical informatics, and survey and study design.”

Undergraduate students who plan to apply for a graduate epidemiology program might consider majoring in biology, social science, or public policy and social services.

Others who enter the epidemiology field are medical professionals. Nurses who earn a master’s degree in clinical epidemiology can use their skills as a nurse epidemiologist to ensure patients receive the best possible care with a low risk of infection. They can instruct hospital employees on these best practices and conduct research to determine risk factors for infection. Some epidemiologists also have a degree in medicine, which requires going to medical school.

Degree and training requirements depend on the student’s chosen career path within the epidemiology field.