People are usually well informed about their health status, the positive and negative effects of their behaviour on their health and their use of health care services. Yet their perceptions of their health can differ from what administrative and examination-based data show about levels of illness within populations. Thus, survey results based on self-reporting at the household level complement other data on health status and the use of services. Only one third of adults rated their health as good or very good in Portugal (Kasmel et al., 2004). This is the lowest of the Eur-A countries reporting and reflects the relatively adverse situation of the country in terms of mortality and selected morbidity.