Enclosed is the fourth edition of a book that is dedicated to the medical and social issues of individuals with sickle cell disease. This publication, which was developed by physicians, nurses, psychologists, and social workers who specialize in the care of children and adults with sickle cell disease, describes the current approach to counseling and also to management of many of the medical complications of sickle cell disease. Each chapter was prepared by one or more experts and then reviewed by several others in the field. Additional experts reviewed the entire volume. This book is not the result of a formalized consensus process but rather represents the efforts of those who have dedicated their professional careers to the care of individuals with sickle cell disease. The names of the authors, their affiliations, and their e-mail addresses are listed in the front of the book.