Health is a state of complete physical, mental, and social well-being, not just the absence of disease or infirmity. The World Health Organization (WHO) defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity". Health can be promoted by encouraging healthful activities, such as regular physical exercise and adequate sleep, and by reducing or avoiding unhealthful activities or situations, such as smoking or excessive stress.

The meaning of health has evolved over time. Early definitions of health focused on the theme of the bodys ability to function, and health was seen as a state of normal function that could be disrupted from time to time by disease. In 1984, WHO revised the definition of health and defined it as "the extent to which an individual or group is able to realize aspirations and satisfy needs and to change or cope with the environment. Health is a resource for everyday life, not the objective of living; it is a positive concept, emphasizing social and personal resources, as well as physical capacities".

There are different types of health that a person needs to consider, including physical, mental, emotional, and social health. Good physical health can work in tandem with mental health to improve a person’s overall quality of life. Looking after physical health and well-being also involves reducing the risk of an injury or health issue, such as minimizing hazards in the workplace, using contraception when having sex, practicing effective hygiene, avoiding the use of tobacco, alcohol, or illegal drugs, and taking the recommended vaccines for a specific condition or country when traveling.

In conclusion, health is a complex concept that encompasses physical, mental, and social well-being, and it is not just the absence of disease or infirmity. It is a resource for everyday life, and it can be promoted by encouraging healthful activities and reducing or avoiding unhealthful activities or situations.