Preventive medicine, is a medical discipline which focuses on preventing diseases and promoting a general state of health and well being. In both Europe and the United States, it is considered to be a board specialty, meaning that physicians can focus on preventive medicine while they get their medical degree, and use the skills they learn in school to reduce the outbreak of disease epidemics, improve public health, and increase the general quality of life for individuals all over the world. In the West, preventive medicine is practiced as an arm of public health, and is applied to the whole population, while in Eastern medicine, many doctors practice individual preventive medicine. Individual Western doctors are sometimes criticized for not practicing preventive medicine on a patient by patient basis, because insurance companies often feel that it is too expensive and time consuming, and will not compensate doctors for preventive measures.

When preventive medicine is applied to a whole population, it includes things like extensive work in public health, pest and insect control, vaccinations, food safety, and improvements in hygiene for water supplies, homes, and individuals. As can be seen by looking at this wide variety of topics covered by preventive medicine, a number of specialties are incorporated into successful preventive medicine programs. In developing nations, doctors who specialize in preventive medicine are focused on improving hygiene and living conditions to prevent outbreaks, and on vaccinating and educating the population. In the West, preventive medicine includes extensive research and development, monitoring of food supplies, and well trained epidemiology teams who track down an outbreak at its source when one emerges.

When practiced on an individual basis, preventive medicine involves looking at the body as a whole, rather than at the individual parts of the body. Many Eastern disciplines already view the body this way, and practitioners of traditional Chinese medicine and other similar disciplines work with their patients to keep the body balanced, happy, and healthy. Measures to treat the body as a whole include herbal regimens, massage, psychotherapy, and dietary changes. The West has slowly accepted the value of preventive medicine for individuals, especially with rising obesity rates, and many doctors are starting to incorporate whole body therapy into their practice.

Preventive medicine has a long history all over the world, dating back for centuries to the time when people first realized that unclean water made them sick, and that living conditions needed to be more hygienic to prevent illness. Steps made in the field were small, but important, until the twentieth century, when numerous governments founded disease prevention centers such as the Centers for Disease Control and Prevention in the United States. These scientific establishments began to set firm guidelines designed to minimize the transmission of disease, improve hygiene, and enable rapid responses to major outbreaks.

In addition to medicine and science, preventive medicine also looks at economic and social issues, as some populations are clearly more at risk of contracting dangerous diseases than others. Many sociologists, psychologists, and economists work in the field of preventive medicine to assist people of low income, education, and social status all over the world. Organizations which promote preventive medicine work closely with these individuals in the hopes that all people on earth can enjoy healthy, disease free lives.