**Preface to "ME/CFS: Causes, Clinical Features and Diagnosis"**

This volume aims to focus on the early stages of ME/CFS and the underlying factors predisposing to it, by addressing the causes of the illness, its clinical features, and diagnosis. We were motivated both by the plight of the individual patient, and also by the impact of the illness on society as a whole. We have reason to believe that patients and their families and carers frequently experience difficulties accessing care, and are subject to discriminatory attitudes on the parts of care providers and others. We also wish to create awareness of the impact of ME/CFS on society as a whole, which is considerable, in terms of both costs and social disruption. We also explore ways to reduce the public health burden of ME/CFS, and to mitigate the damaging effects of the illness on individual patients and their families.

Our aim is to provide content in this volume that will be of interest both to those undertaking scientific research and to those providing clinical care for ME/CFS patients. There is also plenty to interest, and provide food for thought, for social policy analysts, policy makers and governments, and those with an interest in social research and medical education. These considerations are of particular importance at the present time, when Long Covid-19 has moved post-viral syndromes to the forefront of the political agenda, and confronted society with new challenges in this area on a hitherto unprecedented scale.

Our themed issue is a truly international effort, with sixty-nine authors contributing from seventeen European countries, Canada, and the USA. We are very grateful to everyone who has contributed their high quality research. I am particularly grateful to my co-editors, Professor Modra Murovska, Professor Ken Friedman and Professor Pawel Zalewski, and also to our production editor at MDPI, Svetlana Miljanovic. Without their help and support, none of this would have been possible.
