What is the science of maintaining and promoting health?

The science that studies human health, its strengthening and preservation, as well as various factors that affect health – hygiene. She appeared relatively recently. Some personal hygiene rules have existed for a very long time, but they were not associated with health. In ancient Egypt and China, many different ways of self-care were invented. Hygiene studies various factors affecting human immunity and health in general. For example, this is the habitat, pollution around a person, and so on.