Violence: a global public health problem

This article is a version of the Introduction to the World Report on Violence and Health, published by the World Health Organization (WHO). It presents a general description about this phenomenon and points some basic questions: concepts and definitions about the theme; the state of knowledge about it; nature and typology on violence; proposal of a quantitative and qualitative approach of an ecological model; responsibilities and functions of the public health sector and its potentiality to prevent and reduce violence in the world; the responsibilities of the nations and the policy makers in a intersetorial point of view; difficulties and obstacles for actuation and challenges for the health sector.