The term ¨health¨ covers a wide area and, has many different connotations.  Being healthy doesn´t only mean not being sick in your day-to-day life.  Health should be understood as a much bigger concept that includes three different levels:  physical, mental and social.

On the physical level: here we´re talking about issues or illnesses related to bodily functions, like the flu, a broken arm, heart problems etc.

On the psychological or mental level: this is related to problems that affect our well-being and mental states like depression, obsessive thoughts etc.

On the social level:  this has to do with our surrounding environment and our relationships with others: family, friends, workmates, acquaintances, etc.

Each of these levels of health influences the other levels. That´s why, if you´re sad (mental level) your body´s defenses will be lower and you´ll have a better chance of getting sick on a physical level, like getting the flu, for example. This also influences your behavior—when you´re sick your mood is lower and you have less desire to work, or be around other people and etc, which is the social level of health.

In understanding your health at all levels, you can see how important it is to take care of yourself and have a healthy lifestyle.