Explain how the understanding of health has changed over time.

The definition of health has been changed over a period of time. Many years ago health was only a matter of concern with physical health. But now health means physical, mental and social health.  

A person is said to be healthy when he is physically, mentally and socially well-being. All the three states are necessary for a person for being fit. When a person is said to be socially well-being he is surrounded with positive kind of people and lives in a hygienic area.

Mental state of a person is also considered to be an important factor. A person should be mentally well because a well and healthy person will take decisions wisely.

answer; preoperational(d)