TABLE 9-9 - Primary Sleep Disorders

Dyssomnias
Primary insomnia	Difficulty falling asleep or staying asleep, or sleeping but feeling as if one has not rested during sleep.
Primary hypersomnia	Excess sleepiness, either sleeping too long at one setting or persistent daytime sleepiness not relieved by napping.
Narcolepsy	Sleep attacks during the daytime coupled with REM sleep intrusions or cataplexy (sudden, reversible bilateral loss of skeletal muscle tone). Daytime naps relieve sleepiness.
Breathing-related sleep disorder	Abnormal breathing during sleep leads to sleep disruption and daytime sleepiness.
Circadian rhythm sleep disorder	Sleep disturbance due to a mismatch between a person's intrinsic circadian rhythm and external sleep-wake demands.
Parasomnias
Nightmare disorder	Repeated episodes of scary dreams that wake a person from sleep, usually occur during REM sleep.
Sleep terror disorder	Repeated episodes of apparent terror during sleep; individuals may sit up, scream, or cry out and appear extremely frightened. They do not usually awaken during the attack. Occurs during delta sleep.
Sleepwalking disorder	Recurrent sleepwalking, often coupled with other complex motor activity.