This report provides a comprehensive assessment of the health of the world's population in 2004. Consistent and comparative description of the burden of diseases and injuries is an important input to health decision-making and planning processes. "The Global Burden of Disease" provides a framework for integrating the available information on mortality and health in populations to assess the comparative importance of diseases and injuries in causing premature death, loss of health and disability in all regions of the world.This report draws upon the extensive databases of the World Health Organization and information provided by Member States to provide detailed estimates of premature mortality, disability and loss of health for 135 causes by age and sex for the world as a whole, for regions of the world, and for countries grouped by average income per capita. It builds on previous assessments for the years 2000-2002 published in "The World Health Reports" and "World Health Statistics."