Idiopathic hypersomnia (IH) is a chronic neurological sleep disorder.
People with IH crave sleep in the daytime, no matter how many hours they sleep at night. They struggle to wake, despite setting multiple alarms, and may have difficulty rising from bed (called sleep inertia). They may start the day feeling extremely groggy (sometimes referred to as sleep drunk), and can experience reduced focus and concentration during waking hours (called brain fog).
People with idiopathic hypersomnia often live without a correct diagnosis for a long time, blaming themselves and struggling to maintain work, studies and relationships.
If you or a loved one has IH or a related sleep disorder, you’ll find understanding and up-to-date information here. (All medical info is reviewed by the sleep specialists and researchers on our Medical and Scientific Advisory Boards.) Explore our site to learn more about the science of sleep and the status of research, download guides for students, find clinical trials, consult the directory of physicians, join our patient registry, and much more.