Parasomnia is a term used to describe a group of sleep disorders involving abnormal behaviours, movements, emotions, perceptions, or experiences that occur during sleep or during the transition between sleep and wakefulness. These events can occur during different stages of sleep and may disrupt the normal sleep cycle, resulting in daytime fatigue, impaired concentration, and reduced quality of life. The severity and frequency of parasomnias can vary considerably from person to person.
In simple terms, parasomnias are things people do while asleep that they would not normally do while awake. To an observer, the person may appear awake, yet they remain asleep or only partially conscious of their actions.
Sleepwalking (Somnambulism)
Sleepwalking involves walking or performing other complex behaviours while still asleep. Individuals may have their eyes open and appear awake, but are generally unaware of their surroundings. Episodes can range from brief wandering around the bedroom to more complex activities such as preparing food, leaving the house, or, in rare cases, even driving a vehicle.
Night Terrors (Sleep Terrors)
Night terrors are sudden episodes of intense fear or panic that usually occur during deep non-REM sleep. Unlike nightmares, which occur during REM sleep and are often remembered, people experiencing a night terror frequently have little or no recollection of the event. Episodes may involve screaming, sweating, a rapid heart rate, and significant distress for family members who witness them.
REM Sleep Behaviour Disorder (RBD)
Normally, the body becomes temporarily paralysed during REM sleep, preventing us from acting out our dreams. In REM Sleep Behaviour Disorder, this protective paralysis is lost, allowing individuals to physically act out vivid dreams. Behaviours may include talking, shouting, punching, kicking, or jumping out of bed. Because injuries can occur to both the sleeper and their bed partner, proper assessment is important.
Sleep Talking (Somniloquy)
Sleep talking involves speaking during sleep without awareness of doing so. The content may range from simple sounds and mumbling to complete sentences or conversations. While usually harmless, it can occasionally be associated with other sleep disorders.
Sleep-Related Eating Disorder (SRED)
People with Sleep-Related Eating Disorder consume food while partially asleep, often with little or no memory of the event the following morning. Individuals may eat unusual food combinations or even consume potentially harmful substances if they are not fully aware of what they are doing.
Sleep Paralysis
Sleep paralysis occurs when a person temporarily experiences an inability to move or speak while falling asleep or upon awakening. Episodes may last a few seconds to several minutes and can be accompanied by vivid hallucinations or a sensation of pressure on the chest. Although frightening, sleep paralysis is generally harmless.
Sexsomnia
Sexsomnia is a parasomnia in which an individual engages in sexual behaviours while asleep and remains unaware of them. This condition can create significant personal, social, and relationship difficulties and may require professional assessment and treatment.
What About Bruxism?
Sleep bruxism (tooth grinding or clenching during sleep) is not technically classified as a parasomnia. Instead, it is considered a sleep-related movement disorder. Nevertheless, it is often discussed alongside parasomnias because it occurs during sleep and may be associated with sleep disruption, stress, certain medications, breathing disturbances, or other sleep disorders. In some people it causes tooth wear, fractured dental work, jaw pain, headaches, or temporomandibular joint (TMJ) problems.
What Causes Parasomnias?
Parasomnias may be triggered or worsened by a variety of factors, including:
- Sleep deprivation
- Stress and anxiety
- Irregular sleep schedules
- Shift work
- Certain medications
- Alcohol or recreational drugs
- Fever or illness
- Underlying sleep disorders such as obstructive sleep apnea
Can Parasomnias Be Treated?
In many cases, yes. Treatment depends on the specific disorder and its underlying cause. Improving sleep habits, reducing stress, maintaining a regular sleep schedule, and treating any associated sleep disorders can often help. In some situations, medication, behavioural strategies, or cognitive behavioural therapy may be recommended.
If parasomnias are frequent, severe, potentially dangerous, or affecting quality of life, consultation with a healthcare professional experienced in sleep medicine is recommended. Accurate diagnosis is often the first step toward improving sleep quality, safety, and overall wellbeing.