This book aims to provide a concise review of the medical aspects of free radical reactions. Until now, there have been extensive reviews of the subject in a physiological, pathophysiological and biochemical context. Here, however, the authors concentrate on the biology of free radical reactions as relevant to medical practice, emphasizing that the topic is not just a branch of basic science. Consequently, a short introduction on chemical and biological aspects is followed by a detailed discussion of the role played by free radical reactions in the pathogenesis and development of several human diseases and in therapeutic possibilities. The summary of data from the literature is supplemented by the authors' own experimental results. The presentation will help medical researchers to notice so far unknown connections among several diseases and to make them aware of the existance of the so-called "free radical diseases".