Disease prevention is a branch of medicine that focuses on helping people avoid contracting diseases, both in individuals and communities. A number of branches of science and medicine are intertwined in this medical discipline, ranging from anthropology, to the study of cultural practices that could promote the spread of disease, to epidemiology, the identification and study of disease. Many nations have prevention programs in their national health framework, since it benefits society as a whole.
Humans have been struggling with disease for thousands of years, and the problem only became more pronounced when people began living in closely crowded areas. As cities grew, so did the diversity of disease, along with a variety of colorful attempts at preventing it. Not until the 1800s did people really begin to understand the process of disease, and start to take steps to prevent its spread and to promote healthy communities, ranging from washing hands between patients to pasteurizing dairy products.