People with a narrow perspective consider health as the absence of disease or disability or biological dysfunction. According to this view (or model), to call someone unhealthy or sick means there should be evidence of a particular illness. Social, emotional and psychological factors are not believed to cause unhealthy conditions. This model is narrow and limits the definition of health to the physical and physiological capabilities that are necessary to perform routine tasks.
According to this definition, the individual is healthy if all the body parts, cells, tissues and organ systems are functioning well and there is no apparent dysfunction of the body. Using this model people view the human body in the same terms as a computer, or mechanical device, when something is wrong you take it to experts who maintain it. Physicians, unlike behavioral experts, often focus on treatment and clinical interventions with medication rather than educational interventions to bring about behavior change.