| Sleep Disturbance | Definition | Defining Characteristics |
| Narcolepsy | Neurological disorder characterized by excessive daytime sleepiness, which includes lapses into sleep and napping | Irrepressible need to sleep; daytime napping; cataplexy; sleep paralysis; hypnagogic hallucinations. |
| REM Sleep Behavior Disorder | The mechanism responsible for paralysis during REM not functioning, resulting in the acting out of dreams. | Dreamers vocalize and act out dreams; violent and active dreams are common; upon awakening the dream is remembered; risk of injury to self and sleeping partners. |
| Obstructive Sleep Apnea Hypopnea | Serious disturbance characterized by a complete absence of air flow (apnea) or reduced air flow (hypopnea). | Upper throat muscles go limp; airway closes; breathing stops for 10 seconds or longer; sleeper awakens, gasping for air. |
| Insomnia | Inability to fall asleep or stay asleep. | Poor sleep quantity or quality; tendency to wake up too early; can’t fall back asleep; not feeling refreshed after a night’s sleep |
| Sleepwalking | Disturbance of non-REM sleep characterized by complex motor behavior during sleep. | Expressionless face; open eyes; may sit up in bed, walk around, or speak gibberish; upon awakening has limited recall |
| Sleep Terrors | Disturbance of non-REM sleep generally occurring in children. | Screaming, inconsolable child; usually no memory of the episode the next day. |
| Problems can arise during both REM and non-REM sleep. This table outlines some of the most common sleep disturbances and their defining characteristics. |