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► Health TopicsBrain and NervesSleep disorders - overview

Sleep disorders - overview

Definition

Sleep disorders are problems with sleeping. These include:

  • Trouble falling or staying asleep
  • Falling asleep at the wrong times
  • Too much sleep
  • Abnormal behaviors during sleep

Causes

There are more than 100 different sleeping and waking disorders. They can be grouped into four 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)

PROBLEMS FALLING AND STAYING ASLEEP

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).

PROBLEMS STAYING AWAKE

People with excessive daytime sleepiness feel tired during the day. Symptoms that are not caused by a lack of sleep or interrupted sleep are called hypersomnia.

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

When no cause for the sleepiness can be found, it is called idiopathic hypersomnia.

PROBLEMS STICKING TO A REGULAR SLEEP SCHEDULE

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.

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

SLEEP-DISRUPTIVE BEHAVIORS

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)

References

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.

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 Mosby; 2015:chap 18.


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