This book presents research findings from epidemiological studies investigating chronic and intractable diseases with unidentifiable causes from a clinical perspective. Each chapter provides the latest findings on specific diseases, including procedures for their study, insights into their causes, risk factors and preventive factors providing a foundation for new ideas and further development as well as establishing treatment procedures. Epidemiological Studies of Specified Rare and Intractable Disease(Nanbyo in Japanese)  is a valuable resource for both new and established researchers as well as students who are seeking information on public health and on environmental and clinical epidemiology.