Sleep medicine is a recent discipline but its field of knowledge is already extensive. This results from the progress made in understanding sleep-wake mechanisms, the development of reliable means of investigation, and advances in our knowledge of the nosology of the disorders of sleep and wakefulness. This volume comprises five sections: the first looks at the semiotics of normal sleep in adults and children, sleep mechanisms and the major physiological functions and mental activity during sleep. The second section is a review of the different means of investigating sleep and wakefulness and the methods of analysis currently available. The third section deals with the disorders of sleep and wakefulness, insomnias, hypersomnias, circadian rhythm sleep disorders and parasomnias. The fourth section describes a number of medical disorders which are either sleep-related or simply exacerbated by sleep: snoring, chronic obstructive lung diseases, restless legs syndrome or periodic limb movement disorder, sleep epilepsies, etc. The final section encompasses disorders which are not sleep-dependent but to which sleep investigations may add further insight, such as mood disorders, certain neurological pathologies, dysautonomias, and again, epilepsy. The appendix contains questionnaires, indexes, and assessment scales designed to assist the clinician in evaluating the different disorders. The present edition, written in English is a complete revision of the two preceding French editions. It represents the work of European and North and South American specialists. Doctors and surgeons interested in sleep, cardiologists, internists, neurologists, ENT specialists, pneumologists, psychiatrists and rheumatologists will find state-of-the-art information on sleep physiology and pathology, with means of evaluation, decision trees and appendices to assist them in their approach to patients affected by disorders of sleep and wakefulness.Billiard, Michel is the author of 'Sleep Physiology, Investigations, and Medicine' with ISBN 9780306474064 and ISBN 0306474069.