Parasomnia Meaning: Types, Causes, and What You Can Do

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Your partner tells you that you sat up in bed last night, had a conversation with nobody, and lay back down. You have no memory of it. Or maybe your child screams in terror at 1 a.m. but cannot be woken or comforted, and remembers nothing in the morning.

These are parasomnias, and they are more common than most people think. About 10 percent of Canadians experience some form of parasomnia at some point in their lives, with higher rates in children. The word itself comes from the Greek "para" (alongside) and the Latin "somnus" (sleep), meaning events that happen alongside sleep rather than during full wakefulness.

At Mattress Miracle, we have been helping Brantford families sleep better since 1997. While parasomnias are a medical issue best addressed with your doctor, the sleep environment, including your mattress, bed frame, and bedroom setup, plays a bigger role in managing them than most people realise.

What Is Parasomnia

Parasomnia is an umbrella term for abnormal behaviours, movements, emotions, perceptions, or dreams that occur during sleep, while falling asleep, or while waking up. Unlike insomnia (trouble falling or staying asleep), parasomnias involve doing things during sleep that you normally would not do.

The key characteristic of most parasomnias is that the person is not fully conscious during the event, even though they may appear awake. Their eyes might be open, they might walk around or talk, but the brain is in a mixed state between sleeping and waking. Most people have little or no memory of the episode afterward.

Parasomnias are classified based on which sleep stage they occur in:

• NREM parasomnias: Occur during non-rapid eye movement sleep (especially deep, slow-wave sleep in stages 3-4). These include sleepwalking, night terrors, and confusional arousals.
• REM parasomnias: Occur during rapid eye movement sleep, when most dreaming happens. These include REM sleep behaviour disorder, nightmare disorder, and sleep paralysis.
• Other parasomnias: Not tied to a specific sleep stage. These include sleep-related eating disorder, sleep enuresis (bedwetting), and exploding head syndrome.

Types of Parasomnias

NREM Parasomnias (Disorders of Arousal)

These occur during the deepest stages of non-REM sleep, typically in the first third of the night when deep sleep is most concentrated.

Sleepwalking (Somnambulism)

The person gets out of bed and walks around while still asleep. Episodes can range from sitting up in bed to walking through the house to attempting to leave the building. Sleepwalkers typically have a blank expression, are difficult to wake, and return to bed on their own. About 4 percent of adults and up to 17 percent of children sleepwalk at some point.

Night Terrors (Sleep Terrors)

The person suddenly sits up in bed and screams, often with a look of intense fear. Heart rate and breathing increase dramatically. Unlike nightmares, the person usually cannot be comforted and does not remember the event in the morning. Night terrors are most common in children ages 3 to 12 and affect about 6 percent of children.

Confusional Arousals

The person partially wakes from deep sleep but remains disoriented and confused. They may talk incoherently, respond slowly, or behave inappropriately. These are sometimes called "sleep drunkenness" and are extremely common in young children (up to 17 percent) and relatively common in adults (about 4 percent).

Sleep-Related Eating Disorder

The person gets up during the night and eats, often unusual food combinations, with little or no memory of it. This is distinct from night eating syndrome, where the person is fully awake. Sleep-related eating disorder can be dangerous if the person uses knives, the stove, or consumes non-food items.

REM Parasomnias

These occur during REM sleep, when the brain is highly active and most vivid dreaming takes place.

REM Sleep Behaviour Disorder (RBD)

Normally, your muscles are temporarily paralysed during REM sleep (called atonia) to prevent you from acting out dreams. In RBD, this paralysis fails, and people physically act out their dreams. This can mean punching, kicking, jumping out of bed, or yelling. RBD is more common in men over 50 and may be an early indicator of neurodegenerative diseases like Parkinson's. This parasomnia carries a real risk of injury to the person or their bed partner.

Nightmare Disorder

Everyone has occasional nightmares, but nightmare disorder involves frequent, disturbing dreams that cause significant distress or impair daytime function. Unlike night terrors, the person wakes up fully from a nightmare and can recall the dream in detail. Nightmare disorder affects about 2 to 6 percent of adults and is more common in people with PTSD, anxiety, or depression.

Sleep Paralysis

The person wakes up (or is falling asleep) but cannot move or speak for seconds to minutes. This is often accompanied by a sense of pressure on the chest, difficulty breathing, and visual or auditory hallucinations. Sleep paralysis occurs when REM atonia (the muscle paralysis of dream sleep) persists into wakefulness. About 8 percent of the population experiences it at least once. It is more common with sleep deprivation, irregular sleep schedules, and sleeping on your back.

Other Parasomnias

Exploding Head Syndrome

A sudden, loud noise (bang, explosion, cymbal crash) perceived in the head while falling asleep or waking up. Despite the dramatic name, it is painless and not dangerous, though it can be frightening. It is caused by a brief burst of neural activity during the sleep-wake transition.

Sleep Talking (Somniloquy)

Talking during sleep is extremely common, affecting up to 66 percent of people at some point. It can occur during any sleep stage and ranges from mumbled nonsense to full, coherent sentences. Sleep talking is generally harmless and does not require treatment unless it disrupts a partner's sleep.

Sleep-Related Hallucinations

Vivid visual, auditory, or tactile hallucinations that occur while falling asleep (hypnagogic) or waking up (hypnopompic). These are distinct from dreams because they feel real and often incorporate the actual bedroom environment. They are more common with sleep deprivation and narcolepsy.

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What Causes Parasomnias

Parasomnias result from the brain getting stuck between sleep stages, or from incomplete transitions between sleeping and waking. Several factors increase the likelihood:

Sleep Deprivation

This is the single biggest trigger for NREM parasomnias. When you are sleep-deprived, your body compensates by spending more time in deep sleep. The deeper and more intense the sleep, the harder it is for the brain to fully wake up, which creates the conditions for sleepwalking, night terrors, and confusional arousals.

Irregular Sleep Schedule

Shift work, jet lag, and inconsistent bedtimes disrupt the brain's ability to transition cleanly between sleep stages. People with irregular schedules have higher rates of virtually every type of parasomnia.

Stress and Anxiety

Emotional stress increases cortisol levels and fragments sleep architecture, making parasomnias more likely. Nightmares and sleep paralysis are particularly sensitive to stress.

Genetics

NREM parasomnias run strongly in families. If one parent is a sleepwalker, a child has a 45 percent chance of sleepwalking. If both parents sleepwalk, the risk rises to 60 percent.

Medications and Substances

Several medications can trigger or worsen parasomnias:

• Sedative-hypnotics (some sleeping pills, particularly zolpidem/Ambien)
• Certain antidepressants (SSRIs can trigger RBD; they can also suppress nightmares)
• Beta-blockers (associated with nightmares)
• Alcohol (fragments sleep and increases NREM parasomnias)

Other Sleep Disorders

Obstructive sleep apnea can trigger parasomnias by causing repeated partial arousals from deep sleep. Treating the apnea often resolves the parasomnia as well.

Diagnosis and Treatment

How Parasomnias Are Diagnosed

Diagnosis typically involves:

1. Clinical history: Detailed description of episodes from the person and their bed partner or family
2. Sleep diary: Two weeks of tracking sleep patterns, episode frequency, and potential triggers
3. Polysomnography: An overnight sleep study with video recording that captures brain activity, muscle tone, and behaviour during episodes
4. Neurological evaluation: For RBD specifically, to screen for early signs of neurodegenerative disease

Treatment Approaches

Treatment depends on the type and severity of the parasomnia.

Medication Options

When behavioural approaches are not enough:

• Clonazepam: Low-dose benzodiazepine, effective for RBD and severe NREM parasomnias. Used cautiously due to dependence risk.
• Melatonin: 3 to 12 mg at bedtime, effective for RBD with fewer side effects than clonazepam. Often tried first, especially in older adults.
• Prazosin: Alpha-1 blocker originally for blood pressure, effective for PTSD-related nightmares.
• Trazodone: Sometimes used for sleep-related eating disorder.

All medication decisions should be made with your doctor or sleep specialist.

Safety and Sleep Environment

For parasomnias that involve movement (sleepwalking, RBD), the sleep environment is critical for preventing injury.

Bedroom Safety Measures

• Remove sharp objects and furniture with hard corners from the path between the bed and door
• Lock windows and exterior doors (consider alarms that alert when opened)
• Place the mattress on the floor if falls from bed are a risk (especially for children and people with RBD)
• Use gates on stairways if sleepwalking occurs
• Keep the bedroom floor clear of obstacles
• Consider a bed rail for people who roll out of bed during RBD episodes

Mattress and Bed Frame Considerations

The type of bed matters for parasomnia safety:

• Low-profile bed frames: Reduce the fall distance if someone rolls or falls out of bed during an episode. A platform frame that sits 12 to 14 inches from the floor is safer than a traditional 24-inch bed height.
• Sturdy construction: People with RBD can thrash violently during episodes. A solid wood or metal bed frame with secure joints handles this better than a lightweight frame.
• Quiet mattress: A mattress with individually wrapped coils produces less noise when the sleeper moves, which reduces the chance of waking a partner during an episode.
• Edge support: Good edge support prevents rolling off the side of the mattress during movement episodes.

For Bed Partners

Sleeping next to someone with a parasomnia can be stressful and physically risky (especially with RBD). Options include:

• A larger mattress (Queen or King) to provide more space between sleepers
• Separate blankets so one person's movement does not pull bedding from the other
• In severe cases, sleeping in separate beds temporarily while treatment takes effect
• Motion isolation mattresses (individually wrapped coils) that minimise transfer of movement

Parasomnias in Children

Most childhood parasomnias are not cause for concern. Night terrors, sleepwalking, and confusional arousals are common in children and usually resolve by adolescence as the brain matures. The most helpful things parents can do:

• Ensure adequate sleep (children need 9 to 12 hours depending on age)
• Maintain a consistent bedtime routine
• Avoid waking a child during a night terror or sleepwalking episode (guide them gently back to bed)
• Secure the bedroom environment for safety
• Do not punish or shame a child for parasomnias. They have no control over these events.

Parasomnia vs Other Sleep Disorders

People sometimes confuse parasomnias with other sleep problems. Understanding the difference helps you know what to discuss with your doctor.

Parasomnia vs insomnia: Insomnia is difficulty falling or staying asleep. Parasomnias involve unusual behaviours during sleep. You can have both at the same time, but they are distinct conditions with different treatments.

Parasomnia vs sleep apnea: Sleep apnea is a breathing disorder that causes repeated airway obstruction. However, the micro-arousals caused by sleep apnea can trigger NREM parasomnias like sleepwalking or confusional arousals. Treating the apnea with CPAP or an oral appliance often resolves the parasomnia too.

Parasomnia vs restless leg syndrome: Restless leg syndrome causes an urge to move your legs while you are still awake, typically in the evening. It disrupts sleep onset but is not classified as a parasomnia because the person is conscious. However, the related condition PLMD (periodic limb movement disorder), where legs twitch rhythmically during sleep, is sometimes grouped with parasomnias.

Parasomnia vs narcolepsy: Narcolepsy involves excessive daytime sleepiness and can include sleep paralysis and hypnagogic hallucinations, which are technically parasomnias. If you experience daytime sleep attacks along with nighttime parasomnia symptoms, narcolepsy should be considered.

When to See a Doctor

Consult a doctor if:

• Episodes are frequent (more than once or twice per month)
• Anyone is at risk of injury (from falls, hitting objects, or violent movements)
• The person is significantly tired during the day despite adequate sleep time
• A bed partner's sleep is chronically disrupted
• Episodes begin in adulthood for the first time (especially physical acting out of dreams, which may suggest RBD)
• There is a family history of neurodegenerative disease combined with dream-enactment behaviour