Causes, incidence, and risk factors: 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:
