DEFININTIONS

Advanced Sleep-Wake Phase: A circadian rhythm disorder where a person falls asleep earlier in the evening and wakes up earlier than the conventional time. 

Bedwetting (Enuresis): Involuntary urination during sleep, which can occur in both children and adults. 

Bruxism: The involuntary grinding or clenching of teeth during sleep. 

CBT-I (Cognitive Behavioral Therapy for Insomnia): A structured program that helps people identify and replace thoughts and behaviors that cause or worsen sleep problems. 

Central Sleep Apnea: A sleep-related breathing disorder where the brain fails to signal the muscles to breathe, leading to interrupted breathing during sleep. 

Child Insomnia: Similar to insomnia, but specifically affecting children, where they have trouble falling asleep or staying asleep throughout the night. 

Child Sleep Apnea: Obstructive sleep apnea occurring in young children, which may require medical treatment. 

Confusional Arousals: Episodes of confusion and disorientation occurring during the transition from sleep to wakefulness. 

Dysphoric Dreams: Dysphoric dreams are dreams that elicit feelings of anxiety, fear, sadness, or general distress. These dreams are characterized by their negative emotional content and can significantly impact a person's mood and sleep quality. Unlike nightmares, which often wake the dreamer, dysphoric dreams may not always result in awakening but still leave the dreamer with lingering negative emotions upon waking. 

Dream: A sequence of thoughts, images, or sensations occurring in a person's mind during sleep. 

Dream Journal: A diary where individuals record their dreams, often used as a tool for studying dream patterns and content. 

Exploding Head Syndrome: A parasomnia where an individual experiences a loud, imaginary noise or explosion in the head just before falling asleep or upon waking. 

Groaning (Catathrenia): Prolonged, groaning sounds made during exhalation while asleep. 

Hypnagogic Hallucinations: Vivid visual, auditory, or tactile experiences that occur at the onset of sleep. 

Hypnotherapy: A therapeutic technique that uses hypnosis to help individuals explore their unconscious mind, which can be used to address recurring nightmares. 

Hypnopompic Hallucinations: Vivid visual, auditory, or tactile experiences that occur upon waking. 

Idiopathic Hypersomnia: Excessive daytime sleepiness without a clear cause, characterized by an uncontrollable need to sleep during the day. 

Image Rehearsal Therapy (IRT): A cognitive-behavioral treatment for nightmares, particularly those associated with PTSD, where patients rehearse positive changes to the content of their nightmares while awake. 

Insomnia: Difficulty falling asleep, staying asleep, or waking up too early and not being able to go back to sleep. This results in poor sleep quality and daytime impairment. 

Insufficient Sleep Syndrome: Chronic sleep deprivation due to consistently failing to get adequate sleep, resulting in daytime sleepiness and impaired functioning. 

Irregular Sleep-Wake Rhythm: A condition where there is no consistent sleep-wake pattern, resulting in fragmented sleep and irregular sleep times. 

Jet Lag: Temporary sleep disorder caused by traveling across multiple time zones, leading to difficulty adjusting to the new time schedule. 

Kleine-Levin Syndrome: A rare disorder involving recurrent episodes of excessive sleepiness and prolonged sleep periods, often accompanied by behavioral changes. 

Long Sleeper: Individuals who require significantly more sleep than the average person to feel refreshed, typically sleeping more than 9 hours per night. 

Lucid Dreaming: A type of dream where the dreamer is aware they are dreaming and may have some control over the dream. 

Narcolepsy: A sleep disorder characterized by excessive daytime sleepiness and sudden, uncontrollable episodes of falling asleep, sometimes accompanied by cataplexy. 

Nocturia: Frequent urination during the night, leading to disrupted sleep. 

Non-24-Hour Sleep-Wake Rhythm: A circadian rhythm disorder where the sleep-wake cycle is not aligned with a 24-hour day, causing sleep times to shift progressively later. 

Non-REM Sleep: The phases of sleep that are not REM, typically divided into stages 1 through 4, with stages 3 and 4 being deep sleep. 

Obstructive Sleep Apnea: A common sleep disorder where the airway becomes blocked during sleep, causing breathing pauses and frequent awakenings. 

Oneirology: The scientific study of dreams. The term comes from the Greek oneiro which means dream. A person that studies oneirology is called an oneirologist. 

Parasomnias: A category of sleep disorders characterized by abnormal movements, behaviors, emotions, perceptions, or dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep. These phenomena can be disruptive and may affect the sleep quality of the individual and sometimes their bed partners. 

Periodic Limb Movements: Repetitive, involuntary muscle movements in the limbs during sleep, which can disrupt sleep. 

PTSD (Post-Traumatic Stress Disorder): A mental health condition triggered by a terrifying event, which can include recurrent, distressing nightmares. 

REM Sleep: Rapid Eye Movement sleep, a phase of sleep characterized by rapid movement of the eyes, increased brain activity, and vivid dreams. 

REM Sleep Behavior Disorder: A disorder in which individuals act out their dreams during REM sleep, which can be potentially dangerous. 

Restless Legs Syndrome: An uncomfortable sensation in the legs accompanied by an irresistible urge to move them, typically occurring at night. 

Short Sleeper: An individual who consistently feels refreshed and alert with less than 6 hours of sleep per night. 

Shift Work Disorder: A sleep disorder caused by working non-traditional hours or shifts that disrupt the body's natural sleep-wake cycle. 

Sleep Architecture: The structure of the various stages of sleep, including the sequence and duration of REM and non-REM stages. 

Sleep Apnea: A sleep disorder where breathing repeatedly stops and starts, often leading to disturbed sleep and can be associated with nightmares. 

Sleep Cycle: The progression through the various stages of non-REM and REM sleep, typically lasting about 90 minutes and repeating several times during a night. 

Sleep Eating Disorder: A parasomnia characterized by eating large amounts of food during sleep without full awareness. 

Sleep Hygiene: Practices and habits that are conducive to sleeping well on a regular basis, such as maintaining a consistent sleep schedule and creating a restful sleeping environment. 

Sleep Leg Cramps: Sudden, intense pain in the legs or feet occurring during sleep. 

Sleep Paralysis: A temporary inability to move or speak while falling asleep or waking up, often accompanied by a feeling of pressure on the chest. 

Sleep Rhythmic Movement: Repeated, rhythmic movements of the body while falling asleep or during sleep. 

Sleep Starts (Hypnic Jerks): Sudden, brief muscle contractions occurring as one is falling asleep, often causing a jerking sensation. 

Sleep Talking (Somniloquy): Talking during sleep, which can occur as a standalone condition or as part of other sleep disorders. 

Sleep Terrors (Night Terrors): Episodes of intense fear and panic during sleep, typically accompanied by screaming, thrashing, and confusion upon waking. 

Sleepwalking (Somnambulism): Getting out of bed and walking around while still asleep, often with little or no memory of the event. 

Snoring: A loud, often disruptive noise caused by vibrating tissues in the throat due to obstructed airflow during sleep. 

Trauma-Focused Therapy: A type of therapy that specifically addresses the effects of trauma, which can include treatment for trauma-related nightmares.