What is illness? Is it a physiological dysfunction, a social label, or a way of experiencing the world? How do the physical, social and emotional worlds of a person change when they become ill? And can there be well-being within illness? In this remarkable and thought-provoking book, Havi Carel explores these questions by weaving together the personal story of her own serious illness with insights and reflections drawn from her work as a philosopher. Carel shows how the concepts and language used to describe illness today are inappropriate and misleading. Too often illness is viewed as a localised biological dysfunction while ignoring the actual experience of the ill person, their fears, their hopes, the way they interact with others and, ultimately, experience life. By focusing on the impact of illness on the ill person's life and reflecting on the experience of illness as lived from within, Carel shows how illness is a life-changing process rather than a limited physiological problem. Carel's fresh approach to illness raises some uncomfortable questions about how we all - whether healthcare professionals or not - view the ill and challenges us to become more thoughtful. "Illness" unravels the tension between the universality of illness and its intensely private, often lonely, nature. It offers a new way of looking at a matter that affects every one of us. For those who are ill, it offers insights on our ability to remain happy within the constraints of illness.