A potentially life-threatening disorder in which the airway narrows. It may be accompanied by a lack of oxygen and a disruption of deep sleep.
Although the exact cause is not known, narcolepsy appears to be a disorder of the part of the brain that controls sleep. It's defined by constant sleepiness and a tendency to sleep at inappropriate times.
Restless Leg Syndrome
Causes very unpleasant sensations in the legs - most often the calves -- while sitting or lying still, especially at bedtime. Affects a person's ability to sleep at night and function normally during the day.
Periodic Limb Movement Disorder
This is the involuntary movement of the legs during sleep. People may not be aware of the disturbance but many brief awakenings do disturb sleep and cause excessive daytime sleepiness.
A term describing a wide range of disruptive, sleep-related events. The most common include sleepwalking and sleep tremors, in which the sleeper is awake enough to act out complex behaviors but still asleep and unaware of his or her activity.
Insomnia is the chronic inability to fall or stay asleep. Insomnia is not a sleep disorder but a symptom of another problem. Insomnia can be caused by a number of factors such as stress, use or misuse of sleeping pills, shift work, medications, and poor sleep habits.