Parasomnia: Nighttime Adventures You Didn’t Sign Up For

Sleep is supposed to be a time for rest, but for some, it becomes a stage for unexpected activities like walking, talking, or even eating — all without conscious awareness. This phenomenon is known as parasomnia, a group of sleep disorders that disrupt the boundaries between sleep and wakefulness. Unlike typical restless nights, parasomnias can lead to behaviours that impact one’s safety, relationships, and overall well-being.

With our demanding schedules, late-night binge-watching sessions, and inconsistent sleep routines, these disorders are becoming more noticeable. Parasomnia isn’t just a medical condition; it’s a reflection of how lifestyle habits and stress can interrupt even our most basic need for restful sleep. Understanding parasomnia means uncovering the delicate balance between our body, mind, and sleep cycles to reclaim those much-needed restorative hours. A recent study published in an Indian journal found that a whopping 88% of kids aged 5-15 are dealing with sleep issues, with parasomnias (sleep disturbances like sleepwalking or night terrors) being the most common problem.

What is parasomnia?

Parasomnia is a category of sleep disorders that cause abnormal behaviours or experiences during sleep, transitions between sleep stages, or while waking up. Unlike typical sleep disturbances, parasomnias often involve complex activities — like walking, talking, or even eating — without the person being aware of their actions. These episodes occur because parts of the brain that regulate movement and emotions are active, even though the person is still asleep.

Parasomnia isn’t a single condition but an umbrella term for various behaviours, ranging from harmless sleep talking to potentially risky actions like sleepwalking or acting out vivid dreams. While it can affect anyone, the intensity and frequency often vary based on age, stress levels, and underlying medical conditions.

By disrupting the restorative processes of sleep, parasomnias can lead to daytime fatigue, impaired focus, and even strained relationships, making it essential to understand and address these disorders.

What is non-rapid eye movement (non-REM) sleep?

Non-rapid eye movement (non-REM) sleep is one of the two main phases of sleep, the other being rapid eye movement (REM) sleep. Non-REM sleep is essential for physical restoration, making up about 75%-80% of your total sleep time. It consists of three stages, each serving a different function in rejuvenating the body and mind. During non-REM sleep, your body undergoes important processes like tissue repair, growth, and immune system strengthening, helping you feel refreshed and energised the next day.

Stages of non-REM sleep

1. Stage 1 (Light sleep):

• The transition between wakefulness and sleep
• Muscle relaxation and slowing of the heart rate begin
• Easy to wake up from, and people may experience hypnic jerks (sudden muscle twitches)

2. Stage 2 (Moderate sleep):

• Body temperature drops, and heart rate stabilises
• Brain activity slows with bursts of rapid brain waves known as sleep spindles
• You become less aware of your surroundings, making it harder to wake up.

3. Stage 3 (Deep sleep):

• The most restorative phase is where physical repair happens
• Tissue repair, immune system strengthening, and hormone release occur
• Difficult to wake someone from this stage, and they feel groggy if disturbed.

What is rapid eye movement (REM) sleep?

REM sleep is characterised by rapid, irregular eye movements, heightened brain activity, and a deep state of relaxation where the body is almost completely paralysed. It typically occurs in bursts throughout the night, with each REM cycle becoming longer as the night progresses.

During REM sleep, the brain is highly active, and vivid dreaming occurs. The heart rate and breathing become more rapid and irregular, similar to waking state patterns, although the body remains in a state of paralysis to prevent acting out dreams. This paralysis serves as a safety mechanism, preventing individuals from physically enacting the vivid scenes and emotions of their dreams. REM sleep is believed to play a crucial role in cognitive functions such as memory consolidation, learning, and emotional regulation. It’s a vital stage for mental recovery and creativity, allowing the mind to process information and resolve emotions that arise during waking hours. Disruptions in REM sleep can lead to cognitive issues, mood disturbances, and poor memory. REM sleep is essential for overall mental and emotional well-being, and adequate REM sleep contributes significantly to a healthy, well-rested state.

Different types of parasomnia

Parasomnia encompasses a wide range of behaviours that occur during sleep, and while some might seem humorous or harmless, others can be disruptive or even dangerous. Here are the most common types of parasomnia:

Sleepwalking (Somnambulism)

Sleepwalking is one of the most well-known parasomnias. During episodes, individuals may walk, sit up, or even leave the house — all while still asleep. Often, sleepwalkers have little to no memory of their actions when they wake up. Sleepwalking typically occurs during the deep stages of non-REM sleep and can range from mild (e.g., sitting up in bed) to more extreme behaviours (e.g., cooking or driving).

Sleep talking (Somniloquy)

Sleep talking involves speaking aloud during sleep without being aware of it. The speech can vary from simple mumbling to complex, coherent sentences. This parasomnia can occur during any stage of sleep, though it is more common in lighter stages. While sleep talking is usually harmless, it may disrupt the sleep of others and can be a sign of other underlying issues like stress or sleep deprivation.

Night terrors (Pavor nocturnus)

Night terrors are intense, terrifying episodes that typically occur in children but can affect adults too. Unlike nightmares, which happen during REM sleep and involve vivid dreams, night terrors occur during deep non-REM sleep and involve waking suddenly in a state of panic, often accompanied by screaming, thrashing, or confusion. People experiencing night terrors usually don’t remember the event the next morning.

REM sleep behaviour disorder (RBD)

In REM sleep behaviour disorder, the paralysis that typically accompanies REM sleep (the stage associated with vivid dreaming) is absent, causing the person to physically act out their dreams. This can include violent movements like kicking, punching, or even jumping out of bed. RBD is more common in older adults and may sometimes be linked to neurodegenerative conditions such as Parkinson’s disease.

Sleep eating disorder (SED)

Sleep eating is a parasomnia where individuals eat during the night without realising it. It often involves eating unusual or large quantities of food, and the person is unaware of the behaviour until they wake up and notice the evidence. It’s typically linked to other conditions like sleepwalking or stress, and the person may even consume non-food items.

Sleep paralysis

Sleep paralysis occurs when a person temporarily loses the ability to move or speak as they wake up or fall asleep. During this time, they may experience hallucinations, feel a sense of pressure on their chest, or become aware of a threatening presence. While the person is conscious, their body is still in a state of sleep paralysis that can lead to confusion and anxiety.

Symptoms of parasomnias

The symptoms of parasomnias can vary depending on the type of disorder, but common signs include:

Difficulty sleeping through the night

Frequent awakenings or restlessness can interrupt your sleep cycle, leaving you feeling unrested.

Doing things you wouldn’t typically do when you’re awake while sleeping

This might include activities like sleepwalking or eating, performed unconsciously during sleep.

Feeling strong emotions when waking up (fear, stress, anxiety)

You may experience intense feelings such as panic or distress upon waking, often linked to night terrors.

Feeling tired during the day

Poor sleep quality due to parasomnias can cause daytime fatigue and difficulty concentrating.

Having bad dreams

Having nightmares or disturbing dreams can cause awakening and disrupt peaceful sleep.

Making wakeful movements during sleep (grabbing objects, walking)

Involuntary actions during sleep, such as reaching out or moving around, occur without full awareness.

Making vocalisations (talking, yelling) while sleeping

Talking or shouting during sleep, often without remembering the episode afterwards.

Waking up confused or disoriented

Upon waking, you might feel bewildered or unsure of your surroundings, a common effect of confusional arousal.

The symptoms of parasomnias are usually more noticeable to a partner or family member, as the individual experiencing them may not remember the events. If you notice these behaviours, it is important to seek professional help, as parasomnias can affect both mental and physical health if left untreated.

Causes of parasomnias

Parasomnias can be triggered by a variety of factors, both internal and external. Here are some common causes:

• Genetics: A family history of parasomnias can increase the likelihood of experiencing them, suggesting a genetic predisposition to these sleep disorders.

• Sleep deprivation: Lack of sufficient sleep or irregular sleep patterns can trigger parasomnia episodes. Sleep deprivation can make the brain more prone to abnormalities during sleep, increasing the likelihood of disorders like sleepwalking or night terrors.

• Stress and anxiety: High levels of stress or emotional distress can lead to disruptions in the sleep cycle, which may contribute to parasomnias, particularly in individuals already prone to sleep disorders.

• Medications and substances: Certain medications, particularly those that affect the nervous system can trigger parasomnias. Substance use, including alcohol, can also lead to sleep disruptions and parasomnia episodes.

• Sleep disorders: Other sleep conditions, such as sleep apnoea, narcolepsy, or restless leg syndrome, can contribute to parasomnias. These disorders disrupt normal sleep patterns and may increase the chances of experiencing episodes like sleepwalking or night terrors.

• Neurological conditions: Conditions like Parkinson's disease, Alzheimer's, or other neurodegenerative diseases can increase the risk of parasomnias, particularly in older adults. These conditions can affect the brain's sleep regulation mechanisms.

• Environmental factors: Noise, temperature, or an uncomfortable sleep environment can disrupt sleep and contribute to parasomnia episodes, especially in people who are already prone to them.

Complications and risk factors

Parasomnias can pose significant challenges beyond disrupted sleep, including the potential for physical injury during episodes such as sleepwalking or night terrors. These disturbances often lead to poor sleep quality, resulting in daytime fatigue, irritability, and impaired cognitive function. Certain factors increase the likelihood of parasomnias, including stress, irregular sleep schedules, use of specific medications, and neurological or psychiatric disorders. Early recognition and management of these risks are important to minimise complications and improve overall well-being.

Are certain parasomnias more common in a certain gender?

Yes, certain parasomnias are more common in specific genders. Sleepwalking and night terrors tend to affect males more frequently, especially in children, though they decrease with age. REM sleep-related parasomnias, like sleep talking, are seen in both genders but might be slightly more common in women. In contrast, REM sleep behaviour disorder (RBD), which involves acting out dreams, is more prevalent in men, particularly older adults. These gender patterns may be influenced by age, health, and genetics.

Frequently Asked Questions

1. What are some symptoms of parasomnia?

Symptoms include sleepwalking, sleep talking, night terrors, or unusual movements during sleep.

2. Can parasomnia be cured?

While it isn’t always curable, effective management strategies are available.

3. Is parasomnia a mental illness?

No, but it may be influenced by mental health conditions.

4. How can I prevent parasomnia episodes?

Prioritise sleep hygiene, manage stress, and follow a regular sleep schedule to prevent parasomnia episodes.