Τhis special issue of the AAEM under the title ‘Pain’ is dedicated to both the theoretical and clinical aspects of pain. The idea underlying this initiative is to examine the clinical as well as the theoretical significance of chronic pain in the broad sense of physical, psychological and social illness. The importance of the contribution of several different disciplines then becomes evident, emphasizing the interdisciplinary nature of chronic pain. In this particular special issue, the authors come from the fields of medicine, physiology and psychology, as well as the social sciences.