By definition, a sleep disorder is a a disturbance that interferes with or interrupts the normal sleep pattern. It may also be something that occurs due to the individual's inability to sleep well. Some common types of sleep disorder are bruxism, insomnia, narcolepsy, sleep apnea, and sleep deprivation.

Bruxism
Bruxism is alson known as "teeth grinding." Teeth grinding may have any of a range of causes. However, teeth grinding may cause enough pain or discomfort during sleep, leading to disrupted sleep. In addition to making daytime tasks difficult to accomplish, bruxism may also:
- wear away the enamel of the teeth
- grind the teeth down
- cause cuts to or swelling of the gums
- cause pain in the jaw

Insomnia
Insomnia has several forms. It is frequently associated with depression and is more common in women than in men. Insomnia may be characterized by
- difficulty falling asleep
- difficulty returning to sleep if sleep is interrupted
- waking before it is time to get up.

Narcolepsy
The inability to maintain wakefulness during the daytime hours. This disorder is characterized by the sudden and uncontrollable urge to sleep. This impulse results in the affected individual falling asleep at inappropriate times. One form of narcolepsy is called "microsleep." Microsleeps may last for only a few seconds, although many episodes of narcolepsy result in longer periods of sleep. People who are affected by narcoplepsy may be treated by scheduling naps during the daytime.

Nightmares and Night Terrors
Nightmares are frightening or distressing dreams, or dreams that may cause intense sorry, which may result in waking the individual attempting to sleep. Night terrors are also characterized by sudden wakefulness due to feelings of anxiety or fear; however, they are unrelated to dreaming because they occur during slow-wave sleep. Although they are unrelated to dreaming, individuals having night terrors frequently experience hallucinations. Night terrors are most frequently experienced by children, although adults may be affected by them as well. Nightmares are more egalitarian, affecting individuals across age groups.

Sleep Apnea
Sleep apnea occurs when an individual has interrupted breathing during sleep,frequently due to the individual's airway being blocked by the tongue or from soft palate problems. Sleep apnea is characterized by loud snoring and cessation of breathing, followed by a gasping sound when breathing resumes. People affected with sleep apnea may be treated with devices that control the soft tissue or through surgery.

Sleep Deprivation
Sleep deprivation occurs when the individual fails to get a sufficient amount of sleep to meet the body's needs, resulting in a daytime sleep deficit. This deficit may be characterized by drowsiness, making mistakes, irritability, or microsleeps. Sleep deprivation may occur if the individual has attempted to stay awake for too many hours at one time, such as on long trips. It may also occur if the individual gets too little sleep over a series of nights. Sleep deprivation may be treated by the individual allowing him or herself to get sufficient natural sleep and waking when the body is refreshed.