[The International Classification of Sleep Disorders, third edition. American Academy of Sleep Medicine. Includes bibliographies and index].

The American Academy of Sleep Medicine Board of Directors published the International Classification of Sleep Disorders, 3rd edition (ICSD -3) in 2014. In the 3rd edition, the most drastic change in the content was the unity of secondary insomnia categories into single "chronic insomnia" category. In the central disorders of hypersomnolence section, the nomenclature for narcolepsy was changed to narcolepsy type 1 and type 2. In the sleep related breathing disorder section, several new diagnostic categories were added, and diagnosis of a sleep related hypoventilation disorder was set to require the confirmation of elevated PaCO2. This manuscript overviews the differences and the similarities in the content between the ICSD-3 and the former edition.