Idiopathic hypersomnia is sleeping too much (hypersomnia) without an obvious cause. It is different from narcolepsy, because idiopathic hypersomnia does not involve suddenly falling asleep or losing muscle control due to strong emotions (cataplexy).

Hypersomnia - idiopathic; Drowsiness - idiopathic; Somnolence - idiopathic

The usual approach is to consider other potential causes of excessive daytime sleepiness.

Other sleep disorders that may cause daytime sleepiness include:

• Isolated sleep paralysis
• Narcolepsy
• Obstructive sleep apnea
• Restless leg syndrome

Other causes of excessive sleepiness include:

• Atypical depression
• Certain medications
• Drug and alcohol use
• Low thyroid function (hypothyroidism)
• Previous head injury

Images

Sleep patterns in younger and older adults

Review Date: 06/10/2011
Reviewed By: Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)