Sleep disorders - overview: MedlinePlus Medical Encyclopedia

P Sleep disorders are problems with sleeping. These include trouble falling or staying asleep, falling asleep at the wrong times, too much sleep, and abnormal behaviors during sleep.

T Causes
P There are more than 100 different sleeping and waking disorders. They can be grouped into 4 main categories:
- Problems falling and staying asleep (insomnia)
- Problems staying awake (excessive daytime sleepiness)
- Problems sticking to a regular sleep schedule (sleep rhythm problem)
- Unusual behaviors during sleep (sleep-disruptive behaviors)
P PROBLEMS FALLING AND STAYING ASLEEP
P Insomnia includes trouble falling asleep or staying asleep. Episodes may come and go, last up to 3 weeks (be short-term), or be long-lasting (chronic).
P PROBLEMS STAYING AWAKE
P Hypersomnia is a condition in which people have excessive daytime sleepiness, meaning that they feel tired during the day. Hypersomnia can also include situations in which a person needs to sleep a lot. This may be due to other medical conditions, but can also be due to a problem in the brain. Causes of this problem include:
- Medical conditions, such as fibromyalgia and low thyroid function
- Mononucleosis or other viral illnesses
- Narcolepsy and other sleep disorders
- Obesity, especially if it causes obstructive sleep apnea
P When no cause for the sleepiness can be found, it is called idiopathic hypersomnia.
P PROBLEMS STICKING TO A REGULAR SLEEP SCHEDULE
P Problems may also occur when you do not stick to a regular sleep and wake schedule. This occurs when people travel between time zones and with shift workers who are on changing schedules, especially nighttime workers.
P Disorders that involve a disrupted sleep schedule include:
- Irregular sleep-wake syndrome
- Jet lag syndrome
- Paradoxical insomnia (the person sleeps a different amount than they think they do)
- Shift work sleep disorder
- Delayed sleep phase, as in teenagers who go to sleep very late at night and then sleep until noon
- Advanced sleep phase, as in older adults who go to sleep early in the evening and wake up very early
P SLEEP-DISRUPTIVE BEHAVIORS
P Abnormal behaviors during sleep are called parasomnias. They are fairly common in children and include:
- Sleep terrors
- Sleepwalking
- REM sleep-behavior disorder (a person moves during REM sleep and may act out dreams)

T Alternative Names
P Insomnia; Narcolepsy; Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag

T Images
- Irregular sleep
- Sleep patterns in the young and aged

T References
P Kryger MH, Rosenberg R, Martin L, Kirsch D. Hypersomnolence. In: Kryger MH, Rosenberg R, Martin L, Kirsch D, eds. Kryger's Sleep Medicine Review. 2nd ed. Philadelphia, PA: Elsevier; 2015:section 4.
P Sateia MJ. International classification of sleep disorders-third edition: highlights and modifications. Chest. 2014;146:1387-1394. PMID: 25367475 www.ncbi.nlm.nih.gov/pubmed/25367475.
P Wakefield TL, Lam DJ, Ishman SL. Sleep apnea and sleep disorders. In: Flint PW, Haughey BH, Lund VJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 18.

T Review Date 1/27/2016
P Updated by: Allen J. Blaivas, DO, Division of Pulmonary, Critical Care, and Sleep Medicine, VA New Jersey Health Care System, Clinical Assistant Professor, Rutger's New Jersey Medical School, East Orange, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

