International Classification of Sleep Disorders (ICSD)

International Classification of Sleep Disorders (ICSD)

« Back to Glossary Index

The International Classification of Sleep Disorders (ICSD) is the authoritative clinical text for the diagnosis of sleep disorders, published by the American Academy of Sleep Medicine. The 3rd edition, ICSD-3, was published in 2014, replacing ICSD-2 (which had replaced ICSD-1 in 2005).

The ICSD-3 groups sleep disorders into six major categories – 1) insomnia, 2) sleep-related breathing disorders, 3) central disorders of hypersomnolence, 4) circadian rhythm sleep-wake disorders, 5) parasomnias, and 6) sleep-related movement disorders. A seventh category is for “other sleep disorders” not captured by the six major categories. Sleep disorders including idiopathic hypersomnia, narcolepsy (both types 1 and 2), and Kleine-Levin syndrome are categorized as “central disorders of hypersomnolence.”

Get SomnusNooze, our e-newsletter

Sign up to receive HF updates, news from the world of sleep research, first-person stories, and more.

You will receive and email from (please check your junk/spam folder if needed) to confirm your subscription to our newsletter through MailChimp. You are not subscribed until you confirm. Thank you for your interest in Hypersomnia Foundation!