Chapter 1 illustrates how defining health and illness involves complexities that exceed initial biomedical orientation. I begin with a summary of the definition of health as provided by the World Health Organization, which sets the stage for health and illness as first biomedical but also as psychosocial and as including social well-being. The WHO definition sets the groundwork for the complexities of defining health and illness and positioning definitions within a framework that implies much depth beyond the biomedical orientation of recognizing and treating symptoms. As a starting point, defining health and illness involves the absence of disease or impairment, but that starting point is only a tiny hint at the necessary breadth in understanding. Health and illness considerations require also recognizing inequalities and disparities as shaped by social, political, economic and environmental factors, resources that are unequally distributed and can be systematically skewed.