For thousands of years, women and men have attempted to explain health and well-being, sickness and disease, life and death. The explanations they have come up with vary considerably according to the circumstances in which they were developed. Often these theories relate to broader beliefs about the make-up of the universe, the nature of human life, issues of predestination and of immortality, and questions of religion and God. Some of them may be more global than other, accounting for a wide range of health issues. Others may be more focused, offering an in-depth analysis of a more restricted range of problems. What all of them try to do is to order and make sense of the variety of health-related experiences people have, and to identify potentially useful health-care interventions.